{"id":26212,"date":"2024-10-20T08:11:56","date_gmt":"2024-10-20T02:41:56","guid":{"rendered":"https:\/\/samacheerkalvi.guide\/?p=26212"},"modified":"2024-10-21T12:43:45","modified_gmt":"2024-10-21T07:13:45","slug":"samacheer-kalvi-12th-chemistry-guide-chapter-3","status":"publish","type":"post","link":"https:\/\/samacheerkalvi.guide\/samacheer-kalvi-12th-chemistry-guide-chapter-3\/","title":{"rendered":"Samacheer Kalvi 12th Chemistry Guide Chapter 3 p-Block Elements \u2013 II"},"content":{"rendered":"

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Chemistry Guide<\/a> Pdf Chapter 3 p-Block Elements \u2013 II Text Book Back Questions and Answers, Notes.<\/p>\n

Tamilnadu Samacheer Kalvi 12th Chemistry Solutions Chapter 3 p-Block Elements \u2013 II<\/h2>\n

12th Chemistry Guide p-Block Elements \u2013 II Text Book Questions and Answers<\/span><\/span><\/h3>\n

Part – I – Text Book Evaluation<\/span><\/p>\n

I. Choose the correct answer<\/span><\/p>\n

1. In which of the following, NH3<\/sub> is not used?
\na) Nessler’s reagent
\nb) Reagent for the analysis of IV group basic radical
\nc) Reagent for the analysis of III group basic radical
\nd) Tollen’s reagent
\nAnswer:
\na) Nessler’s reagent<\/p>\n

2. Which is true regarding nitrogen?
\na) least electronegative element
\nb) has low ionisation enthalpy than oxygen
\nc) d – orbitals available
\nd) ability to form p\u03c0 -p\u03c0 bonds with itself
\nAnswer:
\nd) ability to form p\u03c0 -p\u03c0 bonds with itself<\/p>\n

3. An element belongs to group 15 and 3rd period of the periodic table, its electronic configuration would be
\na) Is\u00b2 2s\u00b2 2p4<\/sup>
\nb) Is\u00b2 2s\u00b2 2p\u00b3
\nc) Is\u00b2 2s\u00b2 2p6<\/sup> 3s2\u00b2 3p\u00b2
\nd) Is\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p\u00b3
\nAnswer:
\nd) Is\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p\u00b3<\/p>\n

4. Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas(B) which spontaneously burn in air giving smoky rings. A and B are respectively
\na) P4<\/sub>(red) and PH3<\/sub>
\nb) P4<\/sub> (white) and PH3<\/sub>
\nc) S8<\/sub> and H2<\/sub>S
\nd) P4<\/sub>(white) and H2<\/sub>S
\nAnswer:
\nb) P4<\/sub> (white) and Ph3<\/sub><\/p>\n

5. On hydrolysis, PCl3<\/sub> gives
\na) H3<\/sub>PO3<\/sub>
\nb) PH3<\/sub>
\nc) H3<\/sub>PO4<\/sub>
\nd) POCl3<\/sub>
\nAnswer:
\na) H3<\/sub>PO3<\/sub><\/p>\n

6. P4<\/sub>O6<\/sub> reacts with cold water to give
\na) H3<\/sub>PO3<\/sub>
\nb) H4<\/sub>P2<\/sub>O7<\/sub>
\nc) HPO3<\/sub>
\nd) H3<\/sub>PO4<\/sub>
\nAnswer:
\na) H3<\/sub>PO3<\/sub><\/p>\n

\"Samacheer<\/p>\n

7. The basicity of pyrophosphorous acid (H4<\/sub>P2<\/sub>O3<\/sub>) is
\na) 4
\nb) 2
\nc) 3
\nd) 5
\nAnswer:
\nb) 2<\/p>\n

8. The molarity of given orthophosphoric acid solution is 2M. Its normality is
\na) 6N
\nb) 4N
\nc) 2N
\nd) none of these
\nAnswer:
\na) 6N
\nNormality = M x basicity =2×3 = 6<\/p>\n

9. Assertion : bond dissociation energy of fluorine is greater than chlorine gas
\nReason : chlorine has more electronic repulsion than flourine
\na) Both assertion and reason are true and reason is the correct explanation of assertion.
\nb) Both assertion and reason are true bu t reason is not the correct explanation of assertion
\nc) Assertion is true bu t reason is false
\nd) Both assertion and reason are false
\nAnswer:
\nd) Both assertion and reason are false The converse is true<\/p>\n

10. Among the following, which is the strongest oxidizing agent?
\na) Cl2<\/sub>
\nb) F2<\/sub>
\nC) Br2<\/sub>
\nd) l2<\/sub>
\nAnswer:
\nb) F2<\/sub><\/p>\n

11. The correct order of the thermal stability of hydrogen halide is (PTA – 4)
\na) Hl > HBr > HCl > HF
\nb) HF > HCl > HBr > HI
\nc) HCl > HF > HBr > HI
\nd) HI > HCl > HF > HBr
\nAnswer:
\nb) HF > HCl > HBr > HI<\/p>\n

12. Which one of the following compounds is not formed?
\na) XeOF4<\/sub>
\nb) XeO3<\/sub>
\nc) XeF2<\/sub>
\nd) NeF2<\/sub>
\nAnswer:
\nd) NeF2<\/sub><\/p>\n

13. Most easily liquefiable gas is
\na) Ar
\nb) Ne
\nc) He
\nd) Kr
\nAnswer:
\nc) He<\/p>\n

\"Samacheer<\/p>\n

14. XeFg on complete hydrolysis produces
\na) XeOF4<\/sub>
\nb) XeO2<\/sub>F2<\/sub>
\nc) XeO3<\/sub>
\nd) XeO2<\/sub>
\nAnswer:
\nc) XeO3<\/sub><\/p>\n

15. Which of the following is strongest acid among all?
\na) HI
\nb) HF
\nc) HBr
\nd) HCl
\nAnswer:
\na) HI
\nReason : H-I bond is weakest.<\/p>\n

16. Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules? (NEET)
\na) Br2<\/sub> > I2<\/sub> > F2<\/sub> > Cl2<\/sub>
\nb) F2<\/sub> > Cl2<\/sub> > Br2<\/sub> > I2<\/sub>
\nc) I2<\/sub> > Br2<\/sub> > Cl2<\/sub> > F2<\/sub>
\nd) Cl2<\/sub> > Br2<\/sub> > F2<\/sub> > I2<\/sub>
\nAnswer:
\nd) Cl2<\/sub> > Br2<\/sub> > F2<\/sub> > I2<\/sub><\/p>\n

17. Among the following the correct order of acidity is (NEET)
\na) HClO2<\/sub> < HClO < HClO3<\/sub> < HClO4<\/sub>
\nb) HClO4<\/sub> < HClO2<\/sub> < HClO < HClO3<\/sub>
\nc) HClO3<\/sub> < HClO4<\/sub> < HClO2<\/sub> < HClO
\nd) HClO < HClO2<\/sub> < HClO3<\/sub> < HClO4<\/sub>
\nAnswer:
\nd) HClO < HClO2<\/sub> < HClO3<\/sub> < HClO4<\/sub><\/p>\n

18. When copper is heated with cone HNOs it produces
\na) Cu (NO3<\/sub>)2<\/sub>, NO and NO2<\/sub>
\nb) Cu (NO3<\/sub>)2<\/sub> and N2<\/sub>O
\nc) Cu (NO3<\/sub>)2<\/sub> and NO2<\/sub>
\nd) Cu (NO3<\/sub>)2<\/sub> and NO
\nAnswer:
\nc) Cu (NO3<\/sub>)2<\/sub> and NO2<\/sub><\/p>\n

II. Answer the following questions.<\/span><\/p>\n

Question 1.
\nWhat is the inert pair effect?
\nAnswer:
\nIn p-block elements, as we go down the group, two electrons present in the valence s-orbital become inert and are not available for bonding (only p-orbital involves chemical bonding). This is called inert pair effect.<\/p>\n

Question 2.
\nChalcogens belong to p-block.
\nAnswer:
\nGive reason.<\/p>\n

    \n
  • Chalcogens belong to p-block elements.<\/li>\n
  • Because their outer electronic configuration is ns\u00b2 np4<\/sup>.<\/li>\n
  • In these elements the last electron enters np orbital.<\/li>\n
  • Hence they belong to p-block elements.<\/li>\n<\/ul>\n

    \"Samacheer<\/p>\n

    Question 3.
    \nExplain why fluorine always exhibits an oxidation state of -1?
    \nAnswer:
    \nFluorine the most electronegative element than other halogens and cannot exhibit any positive oxidation state. Fluorine does not have a d-orbital while other halogens have d-orbitals. Therefore fluorine always exhibits an oxidation state of-1 and others in the halogen family shows +1, +3, +5 and +7 oxidation states.<\/p>\n

    Question 4.
    \nGive the oxidation state of halogen in the following
    \nAnswer:
    \na) OF2<\/sub>
    \nb) O2<\/sub>F2<\/sub>
    \nc) Cl2<\/sub>O3<\/sub>
    \nd) I2<\/sub>O4<\/sub><\/p>\n\n\n\n\n\n\n\n
    Halogen<\/td>\nOxidation State<\/td>\n<\/tr>\n
    OF2<\/sub><\/td>\n-1<\/td>\n<\/tr>\n
    O2<\/sub>F2<\/sub><\/td>\n-1<\/td>\n<\/tr>\n
    Cl2<\/sub>O3<\/sub><\/td>\n+3<\/td>\n<\/tr>\n
    I2<\/sub>O4<\/sub><\/td>\n+4<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Question 5.
    \nWhat are interhalogen compounds? Give examples
    \nAnswer:
    \nEach halogen combines with other halogens to form a series of compounds called interhalogen compounds. For example, Fluorine reacts readily with oxygen and forms difluorine oxide (F2<\/sub>O) and difluorine dioxide (F2<\/sub>O2<\/sub>).<\/p>\n

    Question 6.
    \nWhy fluorine is more reactive than other halogens? (PTA – 1, 3)
    \nAnswer:
    \nFluorine is the most reactive element among halogens. This is due to the low value of F – F bond dissociation energy.<\/p>\n

    Question 7.
    \nGive the uses of helium. (PTA – 2)
    \nAnswer:<\/p>\n

      \n
    1. Helium and oxygen mixture is used by divers in place of air oxygen mixture. This prevents the painful dangerous condition called bends.<\/li>\n
    2. Helium is used to provide an inert atmosphere in the electric arc welding of metals<\/li>\n
    3. Helium has the lowest boiling point hence used in cryogenics (low-temperature science).<\/li>\n
    4. It is much less denser than air and hence used for filling air balloons.<\/li>\n<\/ol>\n

      8. What is the hybridisation of iodine in IF7<\/sub>? Give its structure. (PTA – 5)
      \nAnswer:<\/p>\n\n\n\n\n
      Inter halogen<\/td>\nHybridisation<\/td>\nStructure<\/td>\n<\/tr>\n
      IF7<\/sub><\/td>\nSp3<\/sup>d3<\/sup><\/td>\nPentagonal bipyramidal<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      \"Samacheer<\/p>\n

      9. Give the balanced equation for the reaction between chlorine with cold NaOH and hot NaOH
      \nAnswer:
      \nChlorine reacts with cold NaOH to give sodium hypochlorite
      \n\"Samacheer
      \nChlorine reacts with hot NaOH to give sodium chlorate
      \n\"Samacheer<\/p>\n

      10. How will you prepare chlorine in the laboratory? (PTA – 2)
      \nAnswer:
      \n1. Chlorine is prepared by the action of cone, sulphuric acid on chlorides in presence of manganese dioxide.
      \n4NaCl + MnO2<\/sub> + 4H2<\/sub>SO4<\/sub> \u2192 Cl2<\/sub> + MnCl2<\/sub> + 4NaHSO4<\/sub> + 2H2<\/sub>O<\/p>\n

      2. It can also be prepared by oxidising hydrochloric acid using various oxidising agents such as manganese dioxide, lead dioxide, potassium permanganate or dichromate.
      \nPbO2<\/sub> + 4HCl \u2192 PbCl2<\/sub> + 2H2<\/sub>O + Cl2<\/sub>
      \nMnO2<\/sub> + 4HCl \u2192 MnCl2<\/sub> + 2H2<\/sub>O + Cl2<\/sub>
      \n2KMnO4<\/sub> + 16HCl \u2192 2KCl + 2MnCl + 8H2<\/sub>O + 5Cl2<\/sub>
      \nK2<\/sub>Cr2<\/sub>O7<\/sub> + 14HCl \u2192 2KCl + 2CrCl3<\/sub> + 7H2<\/sub>O + 3Cl2<\/sub><\/p>\n

      3. When bleaching powder is treated with mineral acids chlorine is liberated
      \nCaOCl2<\/sub> + 2HCl \u2192 CaCl2<\/sub> + H2<\/sub>O + Cl2<\/sub>
      \nCaOCl2<\/sub> + H2<\/sub>SO4<\/sub> \u2192 CaSO4<\/sub> + H2<\/sub>O + Cl2<\/sub><\/p>\n

      \"Samacheer<\/strong><\/p>\n

      11. Give the uses of sulphuric acid.
      \nAnswer:
      \nSulphuric acid is used<\/p>\n

        \n
      • In the manufacture of fertilisers, ammonium sulphate and superphosphates.<\/li>\n
      • In the manufacture of other chemicals such as hydrochloric acid, nitric acid etc.,<\/li>\n
      • as a drying agent.<\/li>\n
      • in the preparation of pigments, explosives, etc.,<\/li>\n<\/ul>\n

        12. Give a reason to support that sulphuric acid is a dehydrating agent. (PTA – 1)
        \nAnswer:<\/p>\n

          \n
        • Sulphuric acid is highly soluble in water.<\/li>\n
        • It has a strong affinity towards water.<\/li>\n
        • Hence it can be used as a dehydrating agent.<\/li>\n
        • When dissolved in water, it forms mono (H2<\/sub>SO4<\/sub>.H2<\/sub>O) and dihydrates (H2<\/sub>SO4<\/sub>.2H2<\/sub>O) and the reaction is exothermic.
          \nex
          \nC12<\/sub>H<\/span>22<\/sub>O<\/span>11<\/sub> + H<\/span>2<\/sub>SO<\/span>4<\/sub> \u2192 12C + H<\/span>2<\/sub>SO<\/span>4<\/sub>.11H<\/span>2<\/sub>O
          \n<\/span>HCOOH + H2<\/sub>SO<\/span>4<\/sub> \u2192 CO + H<\/span>2<\/sub>SO<\/span>4<\/sub>.H<\/span>2<\/sub>O<\/span><\/li>\n<\/ul>\n

          13. Write the reason for the anomalous behaviour of Nitrogen.
          \nAnswer:
          \n1. Due to its small size, high electronegativity, high ionisation enthalpy and absence of d-orbitals.<\/p>\n

          2. N, has a unique ability to form p\u03c0 – p\u03c0 multiple bond whereas the heavier members of this group (15) do not form p\u03c0 – p\u03c0 bond, because their atomic orbitals are so large and diffused that they cannot have effective overlapping.<\/p>\n

          3. Nitrogen exists a diatomic molecule with triple bond between the two atoms whereas other elements form single bond in the elemental state.<\/p>\n

          4. N cannot form d\u03c0 – p\u03c0 bond due to the absence of d – orbitals whereas other elements can.<\/p>\n

          14. Write the molecular formula and structural formula for the following molecules
          \nAnswer:
          \na) Nitric add
          \nb) dinitrogen pentoxide
          \nc) phosphoric acid
          \nd) phosphine
          \n\"Samacheer<\/p>\n

          15. Give the uses of argon.
          \nAnswer:
          \nArgon prevents the oxidation of hot filament and prolongs the life in filament bulbs.<\/p>\n

          16. Write the valence shell electronic configuration of group -15 elements.
          \nAnswer:
          \nValence shell electronic configuration of group 15 elements is ns\u00b2np\u00b3<\/p>\n\n\n\n\n\n\n\n\n
          Elements<\/td>\nValence Shell Electronic configuration<\/td>\n<\/tr>\n
          N<\/td>\n2s2<\/sup>p3<\/sup><\/td>\n<\/tr>\n
          P<\/td>\n3s2<\/sup>p3<\/sup><\/td>\n<\/tr>\n
          S<\/td>\n4s2<\/sup>4p3<\/sup><\/td>\n<\/tr>\n
          Sb<\/td>\n5s2<\/sup>5p3<\/sup><\/td>\n<\/tr>\n
          Bi<\/td>\n6s2<\/sup>p3<\/sup><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

          17. Give two equations to illustrate the chemical behaviour of phosphine.
          \nAnswer:
          \nBasic Nature :
          \nPhosphine is weakly basic and forms phosphonium salts.
          \nPH3<\/sub> +HI \u2192 PH4<\/sub> I
          \nPH4<\/sub>I + H2<\/sub>O \\(\\underrightarrow { \\triangle } \\) PH3<\/sub> + H3<\/sub>O+<\/sup> + I–<\/sup>
          \nIt react with halogen to give phosphorous penta halidae
          \nPH3<\/sub> +4Cl2<\/sub> \u2192 PCl5<\/sub> + 3HCl<\/p>\n

          Combustion:
          \nWhen phosphine is heated with air or oxygen it burns to give metaphosphoric acid
          \n\"Samacheer<\/p>\n

          18. Give a reaction between nitric acid and a basic oxide.
          \nAnswer:
          \nNitric acid rects with a basic oxide to form salt and water.
          \n3 FeO + 10HNO3<\/sub> \u2192 Fe (NO3<\/sub>)3<\/sub> + NO + 5H2<\/sub>O<\/p>\n

          \"Samacheer<\/p>\n

          19. What happens when PCl5<\/sub> is heated?
          \nAnswer:
          \nOn heating Phoshorous pentachloride decomposes into phosphorus trichloride and chlorine
          \n\"Samacheer<\/p>\n

          20. Suggest a reason why HF is a weak acid, whereas binary acids of all other halogens are strong acids.
          \nAnswer:<\/p>\n

            \n
          • HF is only slightly ionised, hence it is a weak acid<\/li>\n
          • Other halogen acids are almost completely ionised, hence they are strong acids.<\/li>\n
          • Among halogen acids, the electronegativity difference is maximum (1.9) in HF acid.<\/li>\n
          • Hence the bond between H and F is stronger and the acid HF is weaker.<\/li>\n<\/ul>\n

            21. Deduce the oxidation number of oxygen in hypofluorous acid – HOF.
            \nAnswer:
            \nOxidation number of F = -1
            \nOxidation number of H = +1
            \nOxidation number of O in HOF = x
            \n(+1) + x + (-1) = 0
            \nx = 0
            \nOxidation number of O in HOF = 0<\/p>\n

            22. What type of hybridisation occur in (PTA – 5)
            \na) BrF5<\/sub>
            \nb) BrF3<\/sub><\/p>\n

            23. Complete the following reactions
            \n1. NaCl+ MnO2<\/sub> + H2<\/sub>SO4<\/sub> \u2192
            \n2. NaNO2<\/sub> + HCl \u2192
            \n3. P4<\/sub> + Na0H + H2<\/sub>O \u2192
            \n4. AgNO3<\/sub> + PH3<\/sub> \u2192
            \n5. Mg + HNO3<\/sub> \u2192
            \n\"Samacheer
            \n8. Sb + Cl2<\/sub> \u2192
            \n9. HBr + H2<\/sub>SO4<\/sub> \u2192
            \n10. XeF6<\/sub> + H2<\/sub>O \u2192
            \n11. XeO6<\/sub>4-<\/sup> + Mn2+<\/sup> + H+<\/sup> \u2192
            \n12. XeOF4<\/sub> + SiO2<\/sub> \u2192
            \n\"Samacheer
            \nAnswer:
            \n\"Samacheer
            \n\"Samacheer<\/p>\n

            III. Evaluate yourself<\/span><\/p>\n

            1. Write the products formed in the reaction of nitric acid (both dilute and concentrated) with zinc.
            \n\"Samacheer<\/p>\n

            12th Chemistry Guide p-Block Elements \u2013 II Additional Questions and Answers<\/h3>\n

            Part II – Additional Questions<\/span><\/p>\n

            I. Match the following<\/span><\/p>\n

            1.<\/p>\n\n\n\n\n\n\n\n\n\n\n
            Compound<\/td>\nThe oxidation state of Nitrogen<\/td>\n<\/tr>\n
            i) NH3<\/sub><\/td>\n+2<\/td>\n<\/tr>\n
            ii) N2<\/sub>2<\/td>\n+5<\/td>\n<\/tr>\n
            ii) N2<\/sub>O<\/td>\n+4<\/td>\n<\/tr>\n
            iv) NO<\/td>\n+3<\/td>\n<\/tr>\n
            v) HNO2<\/sub><\/td>\n0<\/td>\n<\/tr>\n
            vi) NO2<\/sub><\/td>\n+1<\/td>\n<\/tr>\n
            vii) HNO3<\/sub><\/td>\n-3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            Answer:<\/p>\n\n\n\n\n\n\n\n\n\n\n
            Compound<\/td>\nOxidation state of Nitrogen<\/td>\n<\/tr>\n
            i) NH3<\/sub><\/td>\n-3<\/td>\n<\/tr>\n
            ii) N2<\/sub>2<\/td>\n0<\/td>\n<\/tr>\n
            ii) N2<\/sub>O<\/td>\n+1<\/td>\n<\/tr>\n
            iv) NO<\/td>\n+2<\/td>\n<\/tr>\n
            v) HNO2<\/sub><\/td>\n+3<\/td>\n<\/tr>\n
            vi) NO2<\/sub><\/td>\n+4<\/td>\n<\/tr>\n
            vii) HNO3<\/sub><\/td>\n+5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            2.<\/p>\n\n\n\n\n\n\n\n\n
            Name<\/td>\nMolecular Formula<\/td>\n<\/tr>\n
            i) Sulpurous acid<\/td>\nH2<\/sub>S2<\/sub>O8<\/sub><\/td>\n<\/tr>\n
            ii) Thiosulphuric acid<\/td>\nH2<\/sub>S2<\/sub>O7<\/sub><\/td>\n<\/tr>\n
            iii) Pyrosulphuric acid<\/td>\nH2<\/sub>S2<\/sub>O6<\/sub><\/td>\n<\/tr>\n
            iv) Marshall’s acid<\/td>\nH2<\/sub>SO3<\/sub><\/td>\n<\/tr>\n
            v) Dithionic acid<\/td>\nH2<\/sub>S2<\/sub>O3<\/sub><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            Answer:<\/p>\n\n\n\n\n\n\n\n\n
            Name<\/td>\nMolecular Formula<\/td>\n<\/tr>\n
            i) Sulpurous acid<\/td>\nH2<\/sub>SO3<\/sub><\/td>\n<\/tr>\n
            ii) Thiosulphuric acid<\/td>\nH2<\/sub>S2<\/sub>O3<\/sub><\/td>\n<\/tr>\n
            iii) Pyrosulphuric acid<\/td>\nH2<\/sub>S2<\/sub>O7<\/sub><\/td>\n<\/tr>\n
            iv) Marshall’s acid<\/td>\nH2<\/sub>S2<\/sub>O8<\/sub><\/td>\n<\/tr>\n
            v) Dithionic acid<\/td>\nH2<\/sub>S2<\/sub>O6<\/sub><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            3.<\/p>\n\n\n\n\n\n\n\n
            Inter Halogen compound<\/td>\nHybridisation<\/td>\n<\/tr>\n
            i) IF5<\/sub><\/td>\nSp3<\/sup>d3<\/sup><\/td>\n<\/tr>\n
            ii) BeF3<\/sub><\/td>\nSp3<\/sup><\/td>\n<\/tr>\n
            iii) IF7<\/sub><\/td>\nSp3<\/sup>d2<\/sup><\/td>\n<\/tr>\n
            iv) ClF<\/td>\nSp3<\/sup>d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            Answer:<\/p>\n\n\n\n\n\n\n\n
            Inter Halogen compound<\/td>\nHybridisation<\/td>\n<\/tr>\n
            i) IF5<\/sub><\/td>\nSp3<\/sup>d2<\/sup><\/td>\n<\/tr>\n
            ii) BeF3<\/sub><\/td>\nSp3<\/sup>d<\/td>\n<\/tr>\n
            iii) IF7<\/sub><\/td>\nSp3<\/sup>d3<\/sup><\/td>\n<\/tr>\n
            iv) ClF<\/td>\nSp3<\/sup><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            4.<\/p>\n\n\n\n\n\n\n\n\n\n
            Compound<\/td>\nStructure<\/td>\n<\/tr>\n
            XeOF2<\/sub><\/td>\nLinear<\/td>\n<\/tr>\n
            XeO3<\/sub><\/td>\nSquare planar<\/td>\n<\/tr>\n
            XeF<\/td>\nPyramidal<\/td>\n<\/tr>\n
            XeOF4<\/sub> I<\/td>\nDistorted octahedron<\/td>\n<\/tr>\n
            XeF4<\/sub>T<\/td>\nT shaped<\/td>\n<\/tr>\n
            XeP6<\/sub><\/td>\nSquare pyramidal<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            Answer:<\/p>\n\n\n\n\n\n\n\n\n\n
            Compound<\/td>\nStructure<\/td>\n<\/tr>\n
            XeOF2<\/sub><\/td>\nT shaped<\/td>\n<\/tr>\n
            XeO3<\/sub><\/td>\nPyramidal<\/td>\n<\/tr>\n
            XeF<\/td>\nLinear<\/td>\n<\/tr>\n
            XeOF4<\/sub><\/td>\nSquare pyramidal<\/td>\n<\/tr>\n
            XeF4<\/sub>T<\/td>\nSquare planar<\/td>\n<\/tr>\n
            XeP6<\/sub><\/td>\nDistorted octahedron<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

            II. Assertion and Reason<\/span><\/p>\n

            i) Both A and R are correct, R explains A.
            \nii) A is correct, R is wrong
            \niii) A is wrong, R is correct
            \niv) Both A and R are correct, but R does not explain A.<\/p>\n

            1. Assertion (A) : Aqueous solution of potash Alum is acidic
            \nReason (R) : Aluminium sulphate undergo hydrolysis. (PTA – 2)
            \nAnswer:
            \ni) Both A and R are correct, R is explanation of A<\/p>\n

            2. Assertion (A) : Elements belonging to group 16 are called chalcogens
            \nReason (R) : Group 16 elements are saltforming elements
            \nAnswer:
            \nii) A is correct, R is wrong
            \nCorrect Reason : Group 16 elements are ore forming elements<\/p>\n

            3. Assertion (A) : Among halogen acids, HF has low melting and boiling points
            \nReason (R) : In HF hydrogen bond is present.
            \nAnswer:
            \niii) A is wrong, R is correct.
            \nCorrect A : Among halogen acids HF has high melting and boiling points.<\/p>\n

            4. Assertion (A) : A small piece of Zinc dissolved in dilute nitric acid but hydrogen gas is not evolved. (PTA – 3)
            \nReason (R) : HNO3<\/sub> is an oxidising agent and this oxidizes hydrogen.
            \nAnswer:
            \nii) A is correct but R is wrong.<\/p>\n

            III. Pick out the Correct statement<\/span><\/p>\n

            1. i) Oxygen is diamagnetic
            \nii) Oxygen forms hydrogen bonds
            \niii) Oxygen exists in two allotropic forms
            \niv) Oxygen exists as a triatomic gas
            \na) (i) &(ii)
            \nb) (ii) & (iii)
            \nc) (iii) & (iv)
            \nd) (i) & (iv)
            \nAnswer:
            \nb) (ii) & (iii)
            \nCorrect statement: (i) Oxygen is paramagnetic (iv) Oxygen exists as a diatomic gas<\/p>\n

            2. i) Sulphur exists in crystalline as well as an amorphous form
            \nii) Rhombic sulphur has a characteristic yellow colour and composed of Sg molecules.
            \niii) When heated slowly above % C monoclinic sulphur is converted into Rhombic sulphur
            \niv) At around 140\u00b0C Rhombic sulphur melts to form mobile pale yellow liquid called X sulphur.
            \na) (i) &(ii)
            \nb) (i) & (iii)
            \nc) (ii) & (iii)
            \nd) (iii) & (iv)
            \nAnswer:
            \na) (i) & (ii)
            \nCorrect statement : (iii) When heated slowly above 96\u00b0C, Rhombic sulphur is converted into monoclinic sulphur
            \n(iv) At around 140\u00b0C the monoclinic sulphur melts to form mobile pale yellow liquid called X sulphur<\/p>\n

            \"Samacheer<\/p>\n

            3. i) H2<\/sub>SO4<\/sub> is a dibasic acid
            \nii) H3<\/sub>PO3<\/sub> is a tribasic acid
            \niii) H3<\/sub>PO4<\/sub> is a dibasic acid
            \niv) H3<\/sub>PO2<\/sub> is a monobasic acid
            \na) (i) & (ii)
            \nb) (ii) & (iii)
            \nc) (iii) & (iv)
            \nd) (i) & (iv)
            \nAnswer:
            \nd) (i) & (iv)
            \nCorrect statement:
            \n(ii) H3<\/sub>PO3<\/sub> is a dibasic acid
            \n(iii) H3<\/sub>PO4<\/sub> is a tribasic acid<\/p>\n

            4. i) Krypton is used in cryogenics.
            \nii) Neon is used in high-speed electronic flashbulbs used by photographers.
            \niii) Helium is used to provide an inert atmosphere in electric arc welding of metals.
            \niv) Radon is used as a source of gamma rays.
            \na) (i) & (ii)
            \nb) (ii) & (iii)
            \nc) (iii) & (iv)
            \nd) (i) & (iv)
            \nAnswer:
            \nc) (iii) & (iv)
            \nCorrect statement: (i) Helium is used in cryogenics
            \n(ii) Xenon is used in high speed electronic flash bulbs used by photographers.<\/p>\n

            IV. Pick out the incorrect statement<\/span><\/p>\n

            1. i) In inter halogen compounds the central atom will be the smaller halogen
            \nii) Interhalogen compounds can be formed only between two halogen atoms.
            \niii) Flourine can act as a central atom.
            \niv) Interhalogens are strong oxidising agents
            \na) (i) & (ii)
            \nb) (i) & (iii)
            \nc) (ii) & (iii)
            \nd) (i) & (iv)
            \nAnswer:
            \nb) (i) & (iii)
            \nCorrect statements:
            \n(i) In interhalogen compounds the central atom will be the larger halogen
            \n(iii) Flourine cannot act as a central atom.<\/p>\n

            2. i) Nitrogen reacts with group 2 metals to form ionic nitrides.
            \nii) Ammonia is less soluble in water.
            \niii) Liquid nitrogen is used in biological preservation.
            \niv) In the conversion of metal oxides to metal ammonia acts as an oxidising agent.
            \na) (i) & (ii)
            \nb) (ii) & (iii)
            \nc) (i) & (iii)
            \nd) (ii) & (iv)
            \nAnswer:
            \nd) (ii) & (iv)
            \nCorrect statements:
            \n(ii) Ammonia is extremely soluble in water.
            \n(iv) In the conversion of metal oxides to metal ammonia acts as a reducing agent<\/p>\n

            \"Samacheer<\/p>\n

            3. i) When reacted with metals, nitric acid liberates hydrogen
            \nii) Chromium when reacted with nitric acid becomes passive due to the formation of nitrate on its surface.
            \niii) In most of the reactions nitric acid acts as an oxidising agent
            \niv) Fuming nitric acid contains oxides of nitrogen
            \na) (i) & (ii)
            \nb) (ii) & (iii)
            \nc) (ii) & (iv)
            \nd) (i) & (iv)
            \nAnswer:
            \na) (i) & (ii)
            \nCorrect statement : (i) When reacted with metals, nitric acid does not liberate hydrogen
            \n(ii) Chromium when reacted with nitric acid becomes passive due to the formation of oxide on its surface<\/p>\n

            4. The rate of decomposition of ozone increases sharply in alkaline solution.
            \nii) In acidic solution ozone exceeds the oxidising power of fluorine and atomic oxygen
            \niii) Considerable amount of ozone is formed in the upper atmosphere by the action of UV light
            \niv) The shape of the Ozone molecule is linear
            \na) (i) &(ii)
            \nb) (ii) & (iii)
            \nc) (iii) & (iv)
            \nd) (i) & (iv)
            \nAnswer:
            \nd) (i) & (iv)
            \nCorrect statement : (i) The rate of decomposition of ozone drops sharply in alkaline solution.
            \n(iv) The shape of the ozone molecule is bent.<\/p>\n

            V. Pick out the odd man out<\/span><\/p>\n

            1. w.r.t oxidation number pick the odd man out.
            \na) HPO3<\/sub>
            \nb) H3<\/sub>PO3<\/sub>
            \nc) H3<\/sub>PO4<\/sub>
            \nd) H4<\/sub>P2<\/sub>O7<\/sub>
            \nAnswer:
            \nb) H3<\/sub>PO3<\/sub> – O.N is +3 while in others the O.N of phosphorous is +5<\/p>\n

            2. w.r.t the reaction with sulphuric acid pick the odd man out
            \na) Gold
            \nb) Silver
            \nc) Platinum
            \nd) Copper
            \nAnswer:
            \nd) Copper – copper reacts with sulphuric acid while others do not<\/p>\n

            \"Samacheer<\/p>\n

            3. w.r.t reactivity pick the odd man out
            \na) F2<\/sub>
            \nb) Cl2<\/sub>
            \nc) Br2<\/sub>
            \nd) I2<\/sub>
            \nAnswer:
            \na) F2<\/sub> – F2<\/sub> is more reactive than other halogens<\/p>\n

            4. w.r.t the ability to form oxoacids pick the odd man out
            \na) fluorine
            \nb) chlorine
            \nc) bromine
            \nd) iodine
            \nAnswer:
            \na) Flour – Fluorine forms only one oxoacid where as other halogens form more than one oxoacid.<\/p>\n

            VI. Choose the best answer.<\/span><\/p>\n

            1. The principal gas present in atmosphere is
            \na) O2<\/sub>
            \nb) N2<\/sub>
            \nC) H2<\/sub>
            \nd) CO2<\/sub>
            \nAnswer:
            \nb) N2<\/sub><\/p>\n

            2. The basicity of hypophosphorous acid is (PTA – 2)
            \na) 1
            \nb) 2
            \nc) 3
            \nd) 4
            \nAnswer:
            \na) 1<\/p>\n

            3. Chile salt petre is
            \na) NaNO2<\/sub>
            \nb) NaNO3<\/sub>
            \nc) KNO2<\/sub>
            \nd) KNO3<\/sub>
            \nAnswer:
            \nb) NaNO3<\/sub><\/p>\n

            4. Indian salt petre is
            \na) NaNO2<\/sub>
            \nb) NaNO3<\/sub>
            \nc) KNO2<\/sub>
            \nd) K.NO3<\/sub>
            \nAnswer:
            \nd) KNO3<\/sub><\/p>\n

            5. Inert character of nitrogen is due to its
            \na) high electronegativity
            \nb) low electro negativity
            \nc) high bonding energy
            \nd) low bonding energv
            \nAnswer:
            \nc) high bonding energy<\/p>\n

            \"Samacheer<\/p>\n

            6. Which of the following is caro’s acid?
            \na) H2<\/sub>S2<\/sub>O8<\/sub>
            \nb) H2<\/sub>S2<\/sub>O7<\/sub>
            \nc) H2<\/sub>SO3<\/sub>
            \nd) H2<\/sub>SO3<\/sub>
            \nAnswer:
            \nc H2<\/sub>SO5<\/sub><\/p>\n

            7. Haber’s process is used for the synthesis of
            \na) NO2<\/sub>
            \nb) HNO3<\/sub>
            \nc) NH3<\/sub>
            \nd) N2<\/sub>O
            \nAnswer:
            \na) NH3<\/sub><\/p>\n

            8. The substance used in cryosurgery for producing low temperature is
            \na) liquid oxygen
            \nb) liquid nitrogen
            \nc) liquid hydrogen
            \nd) liquid ammonia
            \nAnswer:
            \nb) liquid nitrogen<\/p>\n

            9. Urea on hydrolysis gives
            \na) NO2<\/sub>
            \nb) HNO3<\/sub>
            \nc) NH3<\/sub>
            \nd) N2<\/sub>O
            \nAnswer:
            \na) NH3<\/sub><\/p>\n

            10. The catalyst used in Haber’s process is
            \na) Ni
            \nb) Fe
            \nc) Co
            \nd) Pt
            \nAnswer:
            \nb) Fe<\/p>\n

            11. The smell of ammonia is
            \na) rotten egg
            \nb) rotten fish
            \nc) pungent
            \nd) garlic
            \nAnswer:
            \nc) pungent<\/p>\n

            12. Like water, ammonia is a fairly good ionising solvent, because its dielectric constant is
            \na) considerably low
            \nb) considerably high
            \nc) equal to zero
            \nd) equal to one
            \nAnswer:
            \nb) considerably high<\/p>\n

            13. The process used for the manufacture of nitric acid is known as
            \na) Haber’s process
            \nb) Deacon’s process
            \nc) contact process
            \nd) Ostwald’s process
            \nAnswer:
            \nd) Ostwald’s process<\/p>\n

            14. With excess of chlorine, ammonia reacts to give an explosive substance
            \na) N2<\/sub>
            \nb) NH4<\/sub>NO3<\/sub>
            \nc) NH4<\/sub>Cl
            \nd) NCl3<\/sub>
            \nAnswer:
            \nd) NCl3<\/sub><\/p>\n

            15. The deep blue colour compound formed when excess of ammonia is added to aqueous solution of copper sulphate is
            \na) [Cu(NO3<\/sub>)2<\/sub>]
            \nb) [Cu(NH3<\/sub>)2<\/sub>]2+<\/sup>
            \nc) [Cu(NH3<\/sub>)4<\/sub>]2+<\/sup>
            \nd) [Cu(NH3<\/sub>)2<\/sub>]+<\/sup>
            \nAnswer:
            \nc) [Cu(NH3<\/sub>)4<\/sub>]2+<\/sup><\/p>\n

            16. The shape of ammonia molecule is
            \na) tetrahedral
            \nb) pyramidal
            \nc) square planar
            \nd) octahedral
            \nAnswer:
            \nb) pyramidal<\/p>\n

            17. The bond angle in ammonia is
            \na) 104\u00b0
            \nb) 104\u00b028′
            \nc) 107\u00b0
            \nd) 180\u00b0
            \nAnswer:
            \nc) 107\u00b0<\/p>\n

            \"Samacheer<\/p>\n

            18. The colour of Pure nitric acid is
            \na) colourless
            \nb) brown
            \nc) pale green
            \nd) green
            \nAnswer:
            \na) colourless<\/p>\n

            19. Fuming nitric acid contains oxides of
            \na) sulphur
            \nb) hydrogen
            \nc) nitrogen
            \nd) carbon
            \nAnswer:
            \nc) nitrogen<\/p>\n

            20. Nitric acid can act as
            \na) an acid
            \nb) an oxidising agent
            \nc) nitrating agent
            \nd) all of the above
            \nAnswer:
            \nd) all the above<\/p>\n

            21. The formula of hyponitrous acid is (MARCH 2020)
            \na) H2<\/sub>N2<\/sub>O2<\/sub>
            \nb) H4<\/sub>N2<\/sub>O4<\/sub>
            \nc) HOONO
            \nd) HNO2<\/sub>
            \nAnswer:
            \na) H2<\/sub>N2<\/sub>O2<\/sub><\/p>\n

            22. The oxidising power of oxo acids follows the order
            \na) HOX > HXO2<\/sub> > HXO3<\/sub> > HXO4<\/sub>
            \nb) HXO4<\/sub> > HXO3<\/sub> > HXO2<\/sub> > HOX
            \nc) HXO3<\/sub> > HXO4<\/sub> > HXO2<\/sub> > HOX
            \nd) HOX > HXO4<\/sub> > HXO3<\/sub> > HXO2<\/sub>
            \nAnswer:
            \na) HOX > HXO2<\/sub> > HXO3<\/sub> > HXO4<\/sub><\/p>\n

            23. White phosphorous is kept under
            \na) kerosene
            \nb) water
            \nc) alcohol
            \nd) ether
            \nAnswer:
            \nb) water<\/p>\n

            24. White phosphorous becomes yellow phosphorous due to
            \na) hydrolysis
            \nb) reduction
            \nc) oxidation
            \nd) displacement
            \nAnswer:
            \nc) oxidation<\/p>\n

            25. In the conversion of yellow phosphorous into phosphine, phosphorous acts as
            \na) oxidising agent
            \nb) reducing agent
            \nc) catalyst
            \nd) hydrolysing agent
            \nAnswer:
            \nb) reducing agent<\/p>\n

            26. In the conversion of phosphorous into orthophosphoric acid, the catalyst used is
            \na) Cl2<\/sub>
            \nb) Br2<\/sub>
            \nc) I2<\/sub>
            \nd) F2<\/sub>
            \nAnswer:
            \nc) I2<\/sub><\/p>\n

            27. Which is used in match boxes?
            \na) White phosphorous
            \nb) Red phosphorous
            \nc) Black phosphorous
            \nd) Scarlet phosphorous
            \nAnswer:
            \nb) Red Phosphorous<\/p>\n

            28. The acid having O-O bond in its structure (PTA – 6)
            \na) H2<\/sub>SO3<\/sub>
            \nb) H2<\/sub>S2<\/sub>O6<\/sub>
            \nc) H2<\/sub>S2<\/sub>O8<\/sub>
            \nd) H2<\/sub>S4<\/sub>O6<\/sub>
            \nAnswer:
            \nc) H2<\/sub>S2<\/sub>O8<\/sub><\/p>\n

            29. The smell of phosphine is
            \na) rotten egg
            \nb) rotten fish
            \nc) pungent
            \nd) garlic
            \nAnswer:
            \nb) rotten fish<\/p>\n

            30. The compounds used in Holme’s signal are
            \na) CaC2<\/sub> & Ca3<\/sub>P2<\/sub>
            \nb) AlP & Ca3<\/sub>P2<\/sub>
            \nc) CaC2<\/sub> & P4<\/sub>
            \nd) AlP & P4<\/sub>
            \nAnswer:
            \na) CaC2<\/sub> & Ca3<\/sub>P2<\/sub><\/p>\n

            31. The gases liberated in Holme’s signal are
            \na) C2<\/sub>H2<\/sub> & CH4<\/sub>
            \nb) C2<\/sub>H2<\/sub> & Ph3<\/sub>
            \nc) C2<\/sub>H4<\/sub> & PH3<\/sub>
            \nd) CH4<\/sub> & Ph3<\/sub>
            \nAnswer:
            \nb) C2<\/sub>H2<\/sub> & Ph3<\/sub><\/p>\n

            32. The formula of pyrophosphoric acid is
            \na) H4<\/sub>P2<\/sub>O6<\/sub>
            \nb) H4<\/sub>P2<\/sub>O7<\/sub>
            \nc) H3<\/sub>PO2<\/sub>
            \nd) H3<\/sub>PO3<\/sub>
            \nAnswer:
            \nb) H4<\/sub>P2<\/sub>O7<\/sub><\/p>\n

            \"Samacheer<\/p>\n

            33. Thermodynamically stable allotrophic form of sulphur is
            \na) Rhombic sulphur
            \nb) Monoclinic sulphur
            \nc) Plastic sulphur
            \nd) Colloidal sulphur
            \nAnswer:
            \na) Rhombic sulphur<\/p>\n

            34. The gas found in volcanic eruptions is
            \na) NO2<\/sub>
            \nb) NO
            \nc) SO2<\/sub>
            \nd) SO3<\/sub>
            \nAnswer:
            \nc) SO2<\/sub><\/p>\n

            35. The hybridisation of sulphur in SO2<\/sub> is
            \na) sp
            \nb) sp\u00b2
            \nc) sp\u00b3
            \nd) dsp\u00b2
            \nAnswer:
            \nb) sp\u00b2<\/p>\n

            36. The gas liberated when dilute sulphuric acid reacts with metals is
            \na) SO2<\/sub>
            \nb) SO3<\/sub>
            \nc) H2<\/sub>
            \nd) O2<\/sub>
            \nAnswer:
            \nc) H2<\/sub><\/p>\n

            37. The gas liberated when cone, sulphuric acid reacts with metals is
            \na) SO2<\/sub>
            \nb) SO3<\/sub>
            \nc) H2<\/sub>
            \nd) O2<\/sub>
            \nAnswer:
            \na) SO2<\/sub><\/p>\n

            38. When sulphuric acid reacts with barium chloride solution, the white precipitate formed is
            \na) PbSO4<\/sub>
            \nb) BaSO4<\/sub>
            \nc) (CH3<\/sub>COO)2<\/sub>SO4<\/sub>
            \nd) PbCl2<\/sub>
            \nAnswer:
            \nb) BaSO4<\/sub><\/p>\n

            39. The halogen which exists as a liquid is
            \na) flourine
            \nb) chlorine
            \nc) bromine
            \nd) iodine
            \nAnswer:
            \nc) bromine<\/p>\n

            40. The halogen which exists as a solid is
            \na) flourine
            \nb) chlorine
            \nc) bromine
            \nd) iodine
            \nAnswer:
            \nd) iodine<\/p>\n

            41. Chlorine is manufactured by
            \na) Haber’s process
            \nb) Deacon’s process
            \nc) Contact process
            \nd) Ostwald’s process
            \nAnswer:
            \nb) Deacon’s process<\/p>\n

            \"Samacheer<\/p>\n

            42. The colour of chlorine gas is
            \na) colourless
            \nb) brown
            \nc) greenish yellow
            \nd) pale green
            \nAnswer:
            \nc) greenish yellow<\/p>\n

            43. Aqua regia is a mixture of cone. HCl and cone. HNO3<\/sub> in the ratio
            \na) 1 : 3
            \nb) 3 : 1
            \nc) 2 : 3
            \nd) 3 : 2
            \nAnswer:
            \nb) 3 :1<\/p>\n

            44. The halogen acid which forms hydrogen bond is
            \na) HF
            \nb) HCl
            \nc) HBr
            \nd) HI
            \nAnswer:
            \na) HF<\/p>\n

            45. Among halogen acids, the strongest bond is present in
            \na) HF
            \nb) HCl
            \nc) HBr
            \nd) HI
            \nAnswer:
            \na) HF<\/p>\n

            46. Among halogen acids, the weakest bond is present in
            \na) HF
            \nb) HCl
            \nc) HBr
            \nd) HI
            \nAnswer:
            \nd) HI<\/p>\n

            47. Among halogen acids, the strongest acid is
            \na) HF
            \nb) HCl
            \nc) HBr
            \nd) HI
            \nAnswer:
            \nd) HI<\/p>\n

            48. Among halogen acids, the weakest acid is
            \na) HF
            \nb) HCl
            \nc) HBr
            \nd) HI
            \nAnswer:
            \na) HF<\/p>\n

            49. The correct order of acid strength is
            \na) HF > HCl > HBr > HI
            \nb) HF < HCl < HBr < HI
            \nc) HF > HCl < HBr > HI
            \nd) HF < HCl > HBr < HI
            \nAnswer:
            \nb) HF < HCl < HBr < HI<\/p>\n

            50. Which is more reactive towards hydrogen?
            \na) flourine
            \nb) chlorine
            \nc) bromine
            \nd) iodine
            \nAnswer:
            \na) flourine<\/p>\n

            \"Samacheer<\/p>\n

            51. The number of bond pair and lone pair of electrons present in the interhalogen compound BrF3<\/sub> is
            \na) 1 & 3
            \nb) 3 & 2
            \nC) 5 & 1
            \nd) 7 & 0
            \nAnswer:
            \nb) 3 & 2<\/p>\n

            52. The oxidation number of oxygen in F2<\/sub>O is
            \na) -2
            \nb) -1
            \nc) +2
            \nd) +1
            \nAnswer:
            \nc) +2<\/p>\n

            53. The oxidation number of chlorine in Cl2<\/sub>O7<\/sub> is
            \na) +1
            \nb) +4
            \nc) +6
            \nd) +7
            \nAnswer:
            \nd) +7<\/p>\n

            54. The strongest oxidising agent among the following is
            \na) chlorous acid
            \nb) chloricacid
            \nc) hypochlorous acid
            \nd) perchloric acid
            \nAnswer:
            \nc) hypochlorous acid<\/p>\n

            55. The first ionisation energy of noble gases is in the order
            \na) He < Ne < Ar < Kr
            \nb) He > Ne > Ar > Kr
            \nc) He < Ne > Ar < Kr
            \nd) He > Ne < Ar > Kr
            \nAnswer:
            \nb) He > Ne > Ar > Kr<\/p>\n

            56. Among noble gases, chemical reactivity is shown by
            \na) He & Ne
            \nb) Ar & Kr
            \nc) Kr & Xe
            \nd) Xe & Rn
            \nAnswer:
            \nc) Kr & Xe<\/p>\n

            57. Which among the following is used in cryogenics?
            \na) He
            \nb) Ne
            \nc) Ar
            \nd) Kr
            \nAnswer:
            \na) He<\/p>\n

            58. Which is used for filling air balloons?
            \na) He
            \nb) Ne
            \nc) Ar
            \nd) Kr
            \nAnswer:
            \na) He<\/p>\n

            \"Samacheer<\/p>\n

            59. Which is used in advertisement sign boards?
            \na) He
            \nb) Ne
            \nc) Ar
            \nd) Kr
            \nAnswer:
            \nb) Ne<\/p>\n

            60. Lamps used in airports as approaching lights is filled with
            \na) He
            \nb) Ne
            \nc) Ar
            \nd) Kr
            \nAnswer:
            \nd) Kr<\/p>\n

            VII. Two Mark Questions<\/span><\/p>\n

            Question 1.
            \nHow is pure nitrogen gas prepared?
            \nAnswer:
            \nPure nitrogen gas is prepared by the thermal decomposition of sodium azide at about 575 K
            \n2NaN3<\/sub> \\(\\underrightarrow { 573K } \\) 2Na + 3N2<\/sub><\/p>\n

            Question 2.
            \nNitrogen does not form any penta halides like phosphorus, why?
            \nAnswer:
            \nNitrogen does not form pentahalide although it exhibit +5 oxidation state. Due to the absence of d-orbitals.
            \nIt cannot undergo sp3d hybridization and hence cannot form pentahalides.<\/p>\n

            Question 3.
            \nWhat is Haber’s process?
            \nAnswer:
            \nThe synthesis of ammonia from nitrogen and hydrogen at high pressure and optimum temperature in presence of iron catalyst is known as Haber’s process.
            \n\"Samacheer
            \n\u2206Hf<\/sub> = -46.2 Kjmol-1<\/sup><\/p>\n

            Question 4.
            \nWrite the uses of nitrogen
            \nAnswer:
            \nNitrogen is used
            \nIn the manufacture of ammonia, nitric acid, and calcium cyanamide etc.
            \nLiquid nitrogen is used for producing low temperature required in cryosurgery and so used in biological preservation.<\/p>\n

            Question 5.
            \nHow is ammonia prepared in the laboratory?
            \nAnswer:
            \nAmmonia is prepared in the laboratory by heating an ammonium salt with a base
            \n2NH4<\/sub>Cl + CaO \u2192 CaCl2<\/sub> + 2NH3<\/sub> + H2<\/sub>O<\/p>\n

            Question 6.
            \nWrite about the reducing property of ammonia.
            \nAnswer:
            \nWhen passed over heated metallic oxides Ammonia reduces metal oxides into metal
            \n3PbO + 2NH3<\/sub> \u2192 3Pb + N2<\/sub> + 3H2<\/sub>O<\/p>\n

            Question 7.
            \nWhat happens when ammonia reacts with excess of chlorine?
            \nAnswer:
            \nWith excess of chlorine ammonia reacts to give an explosive substance nitrogen trichloride
            \n2NH3<\/sub> + 6Cl2<\/sub> \u2192 2NO3<\/sub> + 6HO<\/p>\n

            Question 8.
            \nOn standing nitric acid becomes yellow in colour why?
            \nAnswer:<\/p>\n

              \n
            • Pure nitric acid is colourless<\/li>\n
            • Fuming nitric acid contains oxides of nitrogen<\/li>\n
            • It decomposes on exposure to sunlight or on being heated into nitrogendioxide, water and oxygen.
              \n4HNO3<\/sub> \u2192 4NO2<\/sub> + 2H2<\/sub>O + O2<\/sub><\/li>\n
            • Due to this reaction, pure nitric acid or its concentrated solution becomes yellow on standing<\/li>\n<\/ul>\n

              Question 9.
              \nProve that nitric acid is an oxidising agent.
              \nAnswer:
              \nNon metals like carbon, sulphur are oxidised by nitric acid.
              \nC + 4HNO3<\/sub> \u2192 CO2<\/sub> + 4NO2<\/sub> + 2H2<\/sub>O
              \nS + 2HNO3<\/sub> \u2192 H2<\/sub>SO4<\/sub> + 2NO<\/p>\n

              \"Samacheer<\/p>\n

              Question 10.
              \nProve that nitric acid is a nitrating agent.
              \nAnswer:
              \nNitric acid replaces hydrogen atom from organic compounds with nitronium ion NO2<\/sub>+<\/sup>. This is called nitration.
              \n\"Samacheer<\/p>\n

              Question 11.
              \nWrite the uses of nitric acid is used
              \nAnswer:<\/p>\n

                \n
              • as an oxidising agent.<\/li>\n
              • in the preparation of aqua regia.<\/li>\n
              • Salts of nitric acid are used in photography (AgNO3<\/sub>) and gunpowder for fire arms (NaNO3<\/sub>)<\/li>\n<\/ul>\n

                Question 12.
                \nHow is nitrous oxide prepared?
                \nAnswer:
                \nBy Heating ammonium nitrate nitrous oxide is prepared
                \nNH4<\/sub>NO3<\/sub> \u2192 N2<\/sub>O + 2H2<\/sub>O<\/p>\n

                Question 13.
                \nHow is nitrous acid prepared?
                \nAnswer:
                \nBy treating nitrite salt with acids, nitrous acid is prepared
                \nBa(NO2<\/sub>)2<\/sub> + H2<\/sub>SO4<\/sub> \u2192 2HNO2<\/sub> + BaSO4<\/sub><\/p>\n

                Question 14.
                \nWhat is phosphorescence?
                \nAnswer:
                \nWhite phosphorous undergoes spontaneous slow oxidation in air giving a greenish yellow glow which is visible in the dark. This is known as phosphorescence. The main product of this slow oxidation is P2<\/sub>O3<\/sub>.<\/p>\n

                Question 15.
                \nHow is phosphine prepared?
                \nAnswer:
                \nPhosphine is prepared by the action of sodium hydroxide with white phosphorous in an inert atmosphere of carbon dioxide
                \n\"Samacheer<\/p>\n

                Question 16.
                \nHow is orthophosphoric acid prepared in ‘ the laboratory?
                \nWhen phosphorous is treated with cone, nitric acid in the presence of iodine catalyst, it is oxidised to orthophosphoric acid.<\/p>\n

                Question 17.
                \nWrite the uses of phosphorous Phosphorous is used
                \nAnswer:<\/p>\n

                  \n
                • in match boxes<\/li>\n
                • For the production of certain alloys such as phosphor bronze.<\/li>\n<\/ul>\n

                  Question 18.
                  \nWhat happens when phosphine is heated in the absence of air?
                  \nAnswer:
                  \nPhosphine decomposes into its elements when heated in the absence of air at 317 K
                  \n4PH3<\/sub> \\(\\underrightarrow { 317K } \\) P4<\/sub> + 6H2<\/sub><\/p>\n

                  Question 19.
                  \nWrite about the reducing property of phosphine?
                  \nAnswer:
                  \nPhosphine reduces silver nitrate into silver
                  \nPH3<\/sub> + 6AgNO3<\/sub> + 3H2<\/sub>O \u2192 6Ag + 6HNO3<\/sub> + H3<\/sub>PO3<\/sub><\/p>\n

                  Question 20.
                  \nHow is phosphorous trichloride prepared?
                  \nAnswer:<\/p>\n

                    \n
                  • When a slow stream of chlorine is passed over white phosphorous, PCl3<\/sub> is obtained.<\/li>\n
                  • It is also prepared by treating white phosphorous with thionyl chloride.
                    \nP4<\/sub> + 8SOCl2<\/sub> \u2192 4PCl3<\/sub> + 4SO2<\/sub> + 2S2<\/sub>Cl2<\/sub><\/li>\n<\/ul>\n

                    Question 21.
                    \nOzone (O3<\/sub>) acts as a powerful oxidizing agent why? (PTA – 5)
                    \nAnswer:
                    \nOzone is not a very stable compound under normal conditions and decomposes readily on heating to give a molecule of oxygen and nascent oxygen.
                    \nNascent oxygen, being a free radical, is very reactive
                    \nO3<\/sub> \\(\\underrightarrow { \\triangle } \\) O2<\/sub> + [O]<\/p>\n

                    Question 22.
                    \nWrite the uses of oxygen
                    \nAnswer:<\/p>\n

                      \n
                    • Oxygen is one of the essential components for the survival of living organisms.<\/li>\n
                    • Oxygen is used in oxyacetylene welding.<\/li>\n
                    • Liquid oxygen is used as a rocket fuel.<\/li>\n<\/ul>\n

                      Question 23.
                      \nHow is sulphur dioxide prepared in the laboratory?
                      \nAnswer:
                      \nSO2<\/sub>\u00a0is prepared in the laboratory by treating a metal or metal sulphite with sulphuric acid
                      \nCu + 2H2<\/sub>SO4<\/sub> \u2192 CuSO4<\/sub> + SO2<\/sub> + 2H2<\/sub>O
                      \nSO3<\/sub>2-<\/sup> + 2H+<\/sup> \u2192 SO2<\/sub> + H2<\/sub>O<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 24.
                      \nIllustrate the oxidising property of SO2<\/sub>.
                      \nAnswer:
                      \nSO2<\/sub> oxidises hydrogen sulphide to sulphur and magnesium to magnesium oxide.
                      \n2H2<\/sub>S + SO2<\/sub> \u2192 3S + 2H2<\/sub>O
                      \n2Mg + SO2<\/sub> \u2192 2MgO + S<\/p>\n

                      Question 25.
                      \nWrite about contact process.
                      \nAnswer:<\/p>\n

                        \n
                      • In contact process SO2<\/sub> is oxidised to SO3<\/sub><\/li>\n
                      • It is used in the manufacture of sulphuric acid.
                        \n\"Samacheer<\/li>\n<\/ul>\n

                        Question 26.
                        \nWrite the uses of sulphurdioxide.
                        \nAnswer:<\/p>\n

                          \n
                        • SO2<\/sub> is used in bleaching hair, silk, wool etc.<\/li>\n
                        • SO2<\/sub> is used for disinfecting crops and plants in agriculture<\/li>\n<\/ul>\n

                          Question 27.
                          \nWrite about the structure of sulphr dioxide.
                          \nAnswer:<\/p>\n

                            \n
                          • Sulphur undergoes sp\u00b2 hybridisation.<\/li>\n
                          • A double bond arises between S and O due to p\u03c0 – d\u03c0 overlapping<\/li>\n<\/ul>\n

                            \"Samacheer<\/p>\n

                            Question 28.
                            \nIllustrate the dehydrating property of sulphuric acid.
                            \nAnswer:
                            \n\"Samacheer<\/p>\n

                            Question 29.
                            \nShow that sulphuric acid is a dibasic acid.
                            \nAnswer:
                            \nH2<\/sub>SO4<\/sub> forms two types of salts with NaOH Hence it is dibasic.
                            \n\"Samacheer<\/p>\n

                            Question 30.
                            \nHow is chlorine is manufactured by Deacon’s process?
                            \nAnswer:<\/p>\n

                              \n
                            • A mixture of air and hydrochloric acid is passed up a chamber containing a number of shelves, containing pumice stones soaked in cuprous chloride.<\/li>\n
                            • Hot gases at about 723 K are passed through a jacket that surrounds the chamber.
                              \n\"Samacheer<\/li>\n
                            • Chlorine obtained is dilute and used for the manufacture of bleaching powder<\/li>\n<\/ul>\n

                              Question 31.
                              \nWrite about the bleaching action of chlorine.
                              \nAnswer:
                              \nChlorine is a strong oxidising and bleaching agent since it produces nascent oxygen.
                              \nH2<\/sub>O + Cl2<\/sub> \u2192 HCl + HOCl (Hypochlorous acid)
                              \nHOCl \u2192 HCl +[0]
                              \nColouring matter + Nascent oxygen \u2192 Colourless oxidation product.<\/p>\n

                              The bleaching of chlorine is permanent.<\/p>\n

                              Question 32.
                              \nHow is bleaching powder prepared? (MARCH 2020)
                              \nAnswer:
                              \nBleaching powder is prepared by passing chlorine gas through dry slaked lime (calcium hydroxide)
                              \nCa(OH)2<\/sub> + Cl2<\/sub> \u2192 CaOCl2<\/sub> + H2<\/sub>O<\/p>\n

                              Question 33.
                              \nWrite the uses of chlorine Chlorine is used
                              \nAnswer:<\/p>\n

                                \n
                              • In the purification of drinking water.<\/li>\n
                              • In the bleaching of cotton textiles, paper, and rayon.<\/li>\n
                              • In the extraction of gold and platinum.<\/li>\n<\/ul>\n

                                Question 34.
                                \nHow is hydrochloric and prepared in the laboratory?
                                \nAnswer:
                                \nHydrochloric add is prepared by the action of sodium chloride and cone, sulphuric acid
                                \nNaCl + H2<\/sub>SO4<\/sub> \u2192 NaHSO4<\/sub>. + HCl
                                \nNaHSO4<\/sub> + NaCl \u2192 Na2<\/sub>SO4<\/sub>. + HCl
                                \nDry hydrochloric acid is obtained by passing the gas through cone, sulphuric acid<\/p>\n

                                Question 35.
                                \nHow is xenon trioxide prepared?
                                \nAnswer:
                                \n2XeF6<\/sub> + SiO2<\/sub> \\(\\underrightarrow { 50\u00b0C } \\) 2XeOF4<\/sub> + SiF4<\/sub>
                                \n2XeOF4<\/sub> + SiO2<\/sub> \u2192 2XeO2<\/sub>F2<\/sub> + SiF4<\/sub>
                                \n2XeO2<\/sub>F2<\/sub> + SiO2<\/sub> \u2192 2XeO3<\/sub> + SiF4<\/sub>
                                \n(or)
                                \nXeF6<\/sub> + 3H2<\/sub> \u2192 XeO3<\/sub> + 6HF<\/p>\n

                                Question 36.
                                \nHow is sodium per xenate obtained?
                                \nAnswer:
                                \nWhen XeF6<\/sub> reacts with 2.5 M NaOH, sodium per xenate is obtained.
                                \n2XeF6<\/sub> + 16NaOH \u2192 Na4<\/sub>XeO6<\/sub> + Xe + O2<\/sub> + 12NaF + 8H2<\/sub>O<\/p>\n

                                \"Samacheer<\/p>\n

                                Question 37.
                                \nShow that sodium per xenate is a strong oxidising agent
                                \nAnswer:
                                \nSodium per xenate oxidises manganese (II) ion into permanganate ion even in the
                                \nabsence of a catalyst
                                \n5XeO4-<\/sup>6<\/sub> + 2Mn2+<\/sup> + 14H+<\/sup> \u2192 2MnO–<\/sup>4<\/sub> + 5XeO3<\/sub> + 7H2<\/sub>O<\/p>\n

                                Question 38.
                                \nGive reason: ICl is more reactive than l2<\/sub> (PTA – 3)
                                \nAnswer:<\/p>\n

                                  \n
                                • This is because inter-halogen compounds are in general more reactive than halogens due to w eaker inter-halogen X-X bond than X-X bond.<\/li>\n
                                • So, I2<\/sub> is more stable and less reactive than ICl.<\/li>\n<\/ul>\n

                                  VIII. Three Mark Questions<\/span><\/p>\n

                                  Question 1.
                                  \nWrite about the structure of ammonia.
                                  \nAnswer:<\/p>\n

                                    \n
                                  • Ammonia molecule is pyramidal in shape.<\/li>\n
                                  • Hybridisation of nitrogen is sp\u00b3.<\/li>\n
                                  • The shape must be tetrahedral but in one of the tetrahedral positions a lone pair of electrons from the nitrogen atom is present, hence it is pyramidal.<\/li>\n
                                  • The N – H bond distance is 1.016 A0.<\/li>\n
                                  • The H – H bond distance is 1.645 A\u00b0.<\/li>\n
                                  • The bond angle is 107\u00b0
                                    \n\"Samacheer<\/li>\n<\/ul>\n

                                    Question 2.
                                    \nHow does red phosphorous react with oxygen?
                                    \nAnswer:
                                    \nRed phosphorous reacts with oxygen on heating to give phosphorous trioxide and phosphorous pentoxide.
                                    \nP4<\/sub> + 3O2<\/sub> \u2192 P4<\/sub>O6<\/sub>
                                    \nP4<\/sub> + 5O2<\/sub> \u2192 P4<\/sub>O10<\/sub><\/p>\n

                                    Question 3.
                                    \nHow is pure phosphine prepared?
                                    \nAnswer:
                                    \nPure phosphine is prepared by heating phosphorous acid
                                    \n\"Samacheer<\/p>\n

                                    A pure sample of phosphine is prepared by heating phosphonium iodide with caustic soda solution.
                                    \n\"Samacheer<\/p>\n

                                    Question 4.
                                    \nWhat happens when phosphine is heated with air?
                                    \nAnswer:
                                    \nWhen phosphine is heated with air or oxygen, it undergoes combustion to give meta phosphoric acid.
                                    \n\"Samacheer<\/p>\n

                                    Question 5.
                                    \nWrite about Holmes signal
                                    \nAnswer:<\/p>\n

                                      \n
                                    • In a ship during distress, a container with calcium carbide and calcium phosphide mixture is pierced and thrown into the sea.<\/li>\n
                                    • The mixture reacts with seawater liberating acetylene and phosphine gases.<\/li>\n
                                    • The liberated phosphine catches fire and ignites acetylene.<\/li>\n
                                    • These burning gases with lot of smoke serves as a signal to the approaching ships.<\/li>\n
                                    • This is known as Holme’s signal.<\/li>\n<\/ul>\n

                                      Question 6.
                                      \nWrite about the structure of phosphine
                                      \nAnswer:<\/p>\n

                                        \n
                                      • Phosphorous shows sp\u00b3 hybridisation.<\/li>\n
                                      • Three orbitals are occupied by bond pair electrons.<\/li>\n
                                      • Fourth orbital is occupied by lone pair of electrons.<\/li>\n
                                      • Hence instead of tetrahedral, PH3<\/sub> has a pyramidal shape.<\/li>\n
                                      • Bond angle is reduced to 94\u00b0
                                        \n\"Samacheer<\/li>\n<\/ul>\n

                                        Question 7.
                                        \nHow is oxygen prepared in the laboratory?
                                        \nAnswer:
                                        \nOxygen is prepared in the laboratory by the decomposition of hydrogen peroxide in presence of Mn02 catalyst or by the oxidation of potassium permanganate.
                                        \n\"Samacheer
                                        \n5H2O2<\/sub> + 2MnO4<\/sub>–<\/sup>\u00a0+ 6H+<\/sup>\u00a0\u2192 5O2<\/sub> + 8H2<\/sub>O + 2Mn2+<\/sup><\/p>\n

                                        \"Samacheer<\/p>\n

                                        Question 8.
                                        \nWrite about ozone
                                        \nAnswer:<\/p>\n

                                          \n
                                        • Ozone is an allotropic form of oxygen<\/li>\n
                                        • Ozone is triatomic gas<\/li>\n
                                        • Although negligible amounts of ozone occurs at sea level, it is formed in the upper atmosphere by the action of UV light.<\/li>\n
                                        • In the laboratory ozone is prepared by passing electrical discharge through oxygen.<\/li>\n
                                        • At a potential of 20,000 V about 10% of oxygen is converted into ozone, it gives a mixture known as ozonised oxygen.<\/li>\n
                                        • Pure ozone is obtained as a pale blue gas by the fractional distillation of liquefied ozonised oxygen.
                                          \n\"Samacheer<\/li>\n
                                        • Ozone molecule has a bent shape and symmetrical with delocalised bonding between the oxygen atoms.<\/li>\n<\/ul>\n

                                          \"Samacheer<\/p>\n

                                          Question 9.
                                          \nWrite about the reducing property of sulphur dioxide
                                          \nAnswer:<\/p>\n

                                          SO2<\/sub> reduces chlorine into hydrochloric acid
                                          \nSO2<\/sub> + 2H2<\/sub>O + Cl2<\/sub> \u2192 H2<\/sub>SO4<\/sub> + 2HCl<\/p>\n

                                          SO2<\/sub> reduces potassium permanganate into manganese sulphate (Mn2+<\/sup>).
                                          \n2KMnO4<\/sub> + 5SO2<\/sub> + 2H2<\/sub>O \u2192 K2<\/sub>SO4<\/sub> + 2MnSO4<\/sub> + 2H2<\/sub>SO4<\/sub><\/p>\n

                                          SO2<\/sub> reduces potassium dichromate into chromic sulphate (Cr3+<\/sup>)
                                          \nK2<\/sub>Cr2<\/sub>O7<\/sub> + 3SO2<\/sub> + H2<\/sub>SO4<\/sub> \u2192 K2<\/sub>SO4<\/sub> + Cr2<\/sub>(SO4<\/sub>)3<\/sub> + H2<\/sub>O<\/p>\n

                                          Question 10.
                                          \nWrite about the bleaching action of sulphur dioxide.
                                          \nAnswer:
                                          \nIn presence of water, sulphur dioxide bleaches coloured wool, silk, sponges and straw into colourless due to its reducing property
                                          \n\"Samacheer<\/p>\n

                                          When the bleached product (Colourless) is allowed to stand in air, it is reoxidised by atmospheric oxygen to its original colour.<\/p>\n

                                          Hence bleaching action of sulphurdioxide is temporary<\/p>\n

                                          Question 11.
                                          \nExplain the manufacture of sulphuric acid
                                          \nAnswer:<\/p>\n

                                            \n
                                          • Sulphur dioxide is produced by burning sulphur or iron pyrites in oxygen \/ air
                                            \nS + O2<\/sub> \u2192 SO2<\/sub>
                                            \n4FeS2<\/sub> + 11O2<\/sub> \u2192 2Fe2<\/sub>O3<\/sub> + 8SO2<\/sub><\/li>\n
                                          • SO2<\/sub> is oxidised to SO3<\/sub> by air in presence of V2<\/sub>O5<\/sub> or platinised absestos
                                            \n\"Samacheer<\/li>\n
                                          • SO3<\/sub> is absorbed in cone H2<\/sub>SO4<\/sub> and oleum is produced
                                            \nSO3<\/sub> + H2<\/sub>SO4<\/sub> H2<\/sub>S2<\/sub>O7<\/sub><\/li>\n
                                          • Oleum is converted into sulphuric acid by diluting it with water.
                                            \nH2<\/sub>S2<\/sub>O7<\/sub> + H2<\/sub>O \u2192 2H2<\/sub>SO4<\/sub><\/li>\n
                                          • To maximize the yield the plant is operated at 2 bar pressure and 720 K.
                                            \n96% pure H2<\/sub>SO4<\/sub> is obtained.<\/li>\n<\/ul>\n

                                            Question 12.
                                            \nShow that sulphuric acid is an oxidising agent
                                            \nAnswer:
                                            \nSulphuric acid is an oxidising agent as it produces nascent oxygen
                                            \nH2<\/sub>SO4<\/sub> \u2192 H2<\/sub>O + SO2<\/sub> + [O] (Nascert oxygen)<\/p>\n

                                            Sulphuric acid oxidises carbon into carbon dioxide
                                            \nC + 2H2<\/sub>SO4<\/sub> \u2192 2SO2<\/sub> + 2H2<\/sub>O + CO2<\/sub><\/p>\n

                                            Sulphuric acid oxidises phosphorous into orthophosphoric acid
                                            \nP4<\/sub> + 10H2<\/sub>SO4<\/sub> \u2192 4H3<\/sub>PO4<\/sub> + 10SO2<\/sub> + 4H2<\/sub>0<\/p>\n

                                            Sulphuric acid oxidises iodide into iodine.
                                            \nH2<\/sub>SO4<\/sub> + 2HI \u2192 2SO2<\/sub> + 2H2<\/sub>O + I2<\/sub><\/p>\n

                                            \"Samacheer<\/p>\n

                                            Question 13.
                                            \nWhat is the action of sulphuric acid on metals?
                                            \nAnswer:
                                            \nDilute sulphuric acid reacts with metals liberating hydrogen gas.
                                            \nZn + H2<\/sub>SO4<\/sub> ZnSO4<\/sub> + H2<\/sub> \u2191<\/p>\n

                                            Hot cone. Sulphuric acid reacts with metals to give sulphates and sulphur dioxide
                                            \nCu + 2H2<\/sub>SO4<\/sub> \u2192 CuSO4<\/sub> + 2H2<\/sub>O + SO2<\/sub> \u2191<\/p>\n

                                            Sulphuric acid does not react with noble metals like gold, silver and platinum.<\/p>\n

                                            Question 14.
                                            \nGive the test for sulphate \/ sulphuric acid
                                            \nDilute solution of sulphuric acid \/ Sulphates react with barium chloride or lead acetate solution to give a white precipitate
                                            \n\"Samacheer<\/p>\n

                                            Question 15.
                                            \nHow is chlorine manufactured by the electrolytic process?
                                            \nAnswer:
                                            \nWhen brine solution (NaCl) is electrolyzed, Na+<\/sup> and Cl–<\/sup> ions are formed.
                                            \nNa+<\/sup> ions react with OH–<\/sup> ions of water forming sodium hydroxide.
                                            \nHydrogen and chlorine are liberated as gases.
                                            \nNaCl \u2192 Na+ +Cl–<\/sup>
                                            \nH2<\/sub>O \u2192 H+ +OH–<\/sup>
                                            \nNa+<\/sup> + OH–<\/sup> \u2192 NaOH
                                            \nAt cathode : H+<\/sup> + e–<\/sup> \u2192 H
                                            \nH + H \u2192 H2<\/sub>
                                            \nAt anode : Cl–<\/sup> \u2192 Cl + e–<\/sup>
                                            \nCl + Cl \u2192 Cl2<\/sub><\/p>\n

                                            Question 16.
                                            \nWhat is aqua regia? What is its action on gold?
                                            \nAnswer:
                                            \nAqua regia is a mixture of three parts of cone, hydrochloric acid and one part of cone, nitric acid.
                                            \nThis is used for dissolving gold, platinum etc.
                                            \nAU + 4H+<\/sup> + NO3<\/sub>–<\/sup> + 4Cl–<\/sup> \u2192 AuCl4<\/sub>–<\/sup> +NO + 2H2<\/sub>O<\/p>\n

                                            Question 17.
                                            \nHF acid is a weaker acid at low concentration, but becomes stronger as the concentration increases why?
                                            \nAnswer:
                                            \n0.1 M Solution HF is 10% ionised, hence it is a weak acid.
                                            \nBut 5 M, 15 M solution of HF is stronger due to the equilibrium.
                                            \n\"Samacheer<\/p>\n

                                            At high concentration, the equilibrium involves the removal of flouride ions and increases the hydrogen ion concentration, HF becomes stronger acid as the concentration increases.<\/p>\n

                                            \"Samacheer<\/p>\n

                                            Question 18.
                                            \nHF acid is not stored in glass bottles why? (MARCH 2020)
                                            \nAnswer:
                                            \nHF attacks silica and silicates present in glass bottles.<\/p>\n

                                            Hence HF is not stored in glass bottles. But HF is stored in Teflon bottles.
                                            \nSiO2<\/sub> + 4HF \u2192 SiF4<\/sub> + 2H2<\/sub>O
                                            \nNa2<\/sub>SiO3<\/sub> + 6HF \u2192 Na2<\/sub>SiF6<\/sub> + 3H2<\/sub>O<\/p>\n

                                            Question 19.
                                            \nMention the characteristic of interhalogen compounds (PTA – 2)
                                            \nAnswer:<\/p>\n

                                              \n
                                            • The central atom will be the larger halogen.<\/li>\n
                                            • It can be formed only between two halogens and not more than two halogens.<\/li>\n
                                            • Fluorine can’t act as a central atom because it is the smallest among halogens and highly electronegative.<\/li>\n
                                            • They are strong oxidising agents and undergo auto ionization.<\/li>\n<\/ul>\n

                                              Question 20.
                                              \nGive the preparation of xenon fluorides
                                              \nAnswer:
                                              \n\"Samacheer<\/p>\n

                                              Question 21.
                                              \nWhat is the hybridisation in XeOF2<\/sub>? Give its structure. (PTA – 1)
                                              \nAnswer:<\/p>\n\n\n\n\n
                                              Element<\/td>\nhybridisation<\/td>\nstructure<\/td>\n<\/tr>\n
                                              XeOF2<\/sub><\/td>\nSp3<\/sup>d<\/td>\nT-shaped<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                              IX. Five Mark Questions<\/span><\/p>\n

                                              Question 1.
                                              \nHow is nitric acid manufactured using Ostwald’s process?<\/p>\n

                                                \n
                                              • Ammonia prepared by Haber’s process is mixed about 10 times of air.<\/li>\n
                                              • This mixture is preheated and passed into the catalyst chamber where they come in contact with platinum gauze.<\/li>\n
                                              • The temperature rises about 1275 K.<\/li>\n
                                              • The metallic gauze brings about the rapid catalytic oxidation of ammonia resulting in the formation of NO.<\/li>\n
                                              • NO is oxidized to NO2<\/sub>
                                                \n4NH3<\/sub> +5O2<\/sub> \u2192 4NO + 6H2<\/sub>O +120 KJ
                                                \n2NO + O2<\/sub> \u2192 2NO2<\/sub><\/li>\n
                                              • NO2<\/sub> produced is passed through a series of adsorption towers.<\/li>\n
                                              • NO2<\/sub> reacts with water to give nitric acid.<\/li>\n
                                              • Nitric acid formed is bleached by blowing air.
                                                \n6NO2<\/sub> + 3H2<\/sub>O \u2192 4HNO3<\/sub> + 2NO + H2<\/sub>O<\/li>\n<\/ul>\n

                                                \"Samacheer<\/p>\n

                                                Question 2.
                                                \nExplain the action of nitric acid on metals with one example.
                                                \nPrimary reaction:
                                                \nMetal nitrate is formed with the release of nascent hydrogen.
                                                \n3Cu + 6HNO3<\/sub> \u2192 3CU(NO3<\/sub>)2<\/sub> + 6(H)<\/p>\n

                                                Secondary reaction:
                                                \nNascent hydrogen produces the reduction products of nitric acid
                                                \n6(H) + 3HNO3<\/sub> \u2192 3HNO2<\/sub> + 3H2<\/sub>O<\/p>\n

                                                Tertiary reaction:
                                                \nWith dilute acid, the secondary products decompose to give final products.
                                                \n3HNO2<\/sub> \u2192 HNO3<\/sub> + 2NO + H2<\/sub>O
                                                \nHence overall reaction is
                                                \n3Cu + 8HNO3<\/sub> \u2192 3CU(NO3<\/sub>)2<\/sub> + 2NO + 4H2<\/sub>O<\/p>\n

                                                With concentrated acid the secondary products react to give the final products.
                                                \nHNO2<\/sub> + HNO3<\/sub> \u2192 2NO2<\/sub> + H2<\/sub>O
                                                \nHence overall reaction is
                                                \nCu + 4HNO3<\/sub> \u2192 Cu(NO3<\/sub>)2<\/sub> + 2NO2<\/sub> + 2H2<\/sub>O<\/p>\n

                                                Question 3.
                                                \nWrite the preparation of nitrogen oxides.
                                                \nAnswer:
                                                \n\"Samacheer<\/p>\n

                                                Question 4.
                                                \nWrite the preparation of oxoacids of nitrogen
                                                \nAnswer:
                                                \n\"Samacheer<\/p>\n

                                                Question 5.
                                                \nExplain the structure of oxides of phosphorus
                                                \nAnswer:
                                                \nPhosphorus trioxide :<\/p>\n

                                                  \n
                                                • In P4<\/sub>O6<\/sub>, four phosphorous atoms lie at the corners of a tetrahedron and six oxygen atoms along the edges.
                                                  \nThe P – O bond distance is 165.6 pm which is shorter than the single bond distance of the P-O bond (184 pm)<\/li>\n
                                                • This is due to P\u03c0 – d\u03c0 bonding<\/li>\n
                                                • This results in the considerable double bond character
                                                  \n\"Samacheer<\/li>\n<\/ul>\n

                                                  Phosphorous Pentoxide:<\/p>\n

                                                    \n
                                                  • In P4<\/sub>O10<\/sub> each P atom forms a single bond with three oxygen atoms and a coordinate bond with one oxygen atom.<\/li>\n
                                                  • Terminal coordinate P-O bond length is 143 pm<\/li>\n
                                                  • This is less than the expected single bond distance<\/li>\n
                                                  • This may be due to lateral overlap of filled
                                                    \np – Orbitals of an oxygen atom with empty
                                                    \nd – Orbital on phosphorous.<\/li>\n<\/ul>\n

                                                    \"Samacheer<\/p>\n

                                                    Question 6.
                                                    \nWrite the structure of and basicity oxoacids of phosphorous. (PTA – 3)
                                                    \n\"Samacheer
                                                    \nAnswer:
                                                    \n\"\"
                                                    \n\"Samacheer<\/p>\n

                                                    Question 7.
                                                    \nWrite the preparation of oxoacids of phosphorous
                                                    \nAnswer:
                                                    \n\"Samacheer<\/p>\n

                                                    Question 8.
                                                    \nWrite the structure of oxo acids of sulphur.
                                                    \nAnswer:
                                                    \n\"Samacheer \"Samacheer<\/p>\n

                                                    Question 9.
                                                    \nList any five compounds of Xenon and mention the type of hybridization and structure of the compounds (PTA – 6)
                                                    \nAnswer:<\/p>\n\n\n\n\n\n\n\n\n\n
                                                    Compound<\/td>\nHybridisation<\/td>\nshape\/structure<\/td>\n<\/tr>\n
                                                    1. XeP2<\/sub><\/td>\nsp3<\/sup>d<\/td>\nLinear<\/td>\n<\/tr>\n
                                                    2. XeF4<\/sub><\/td>\nsp3<\/sup>d2<\/sup><\/td>\nSquare planar<\/td>\n<\/tr>\n
                                                    3. XeF6<\/sub><\/td>\nsp3<\/sup>d3<\/sup><\/td>\nDistorted octahedron<\/td>\n<\/tr>\n
                                                    4. XeOF2<\/sub><\/td>\nsp3<\/sup>d<\/td>\nT-shaped<\/td>\n<\/tr>\n
                                                    5. XeOF4<\/sub><\/td>\nsp3<\/sup>d2<\/sup><\/td>\nSquare pyramidal<\/td>\n<\/tr>\n
                                                    6. XeO3<\/sub><\/td>\nsp3<\/sup><\/td>\nPyramidal<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

                                                    Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Chemistry Guide Pdf Chapter 3 p-Block Elements \u2013 II Text Book Back Questions and Answers, Notes. Tamilnadu Samacheer Kalvi 12th Chemistry Solutions Chapter 3 p-Block Elements \u2013 II 12th Chemistry Guide p-Block Elements \u2013 II Text Book Questions and Answers Part – I – Text Book Evaluation …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[5],"tags":[],"class_list":["post-26212","post","type-post","status-publish","format-standard","hentry","category-class-12"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/26212"}],"collection":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/comments?post=26212"}],"version-history":[{"count":1,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/26212\/revisions"}],"predecessor-version":[{"id":41360,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/26212\/revisions\/41360"}],"wp:attachment":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/media?parent=26212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/categories?post=26212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/tags?post=26212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}