{"id":23850,"date":"2024-10-14T11:39:55","date_gmt":"2024-10-14T06:09:55","guid":{"rendered":"https:\/\/samacheerkalvi.guide\/?p=23850"},"modified":"2024-10-15T09:54:13","modified_gmt":"2024-10-15T04:24:13","slug":"samacheer-kalvi-9th-science-guide-chapter-14","status":"publish","type":"post","link":"https:\/\/samacheerkalvi.guide\/samacheer-kalvi-9th-science-guide-chapter-14\/","title":{"rendered":"Samacheer Kalvi 9th Science Guide Chapter 14 Acids, Bases and Salts"},"content":{"rendered":"

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide<\/a> Pdf Chapter 14 Acids, Bases and Salts Text Book Back Questions and Answers, Notes.<\/p>\n

Samacheer Kalvi 9th Science Solutions Chapter 14 Acids, Bases and Salts<\/h2>\n

9th Science Guide Acids, Bases and Salts Text Book Back Questions and Answers<\/h3>\n

I. Choose the correct answer :<\/span>
\n\"
\nQuestion 1.
\nZn + 2HCl \u2192 ZnCl2<\/sub> + ….\u2191 (H2<\/sub>, O2<\/sub>, CO2<\/sub>)
\nAnswer:
\nH2<\/sub><\/p>\n

Question 2.
\nApple contains malic acid. Orange contains …………………(citric acid, ascorbic acid).
\nAnswer:
\nascorbic acid<\/p>\n

Question 3.
\nAcids in plants and animals are organic acids. Whereas Acids in rocks and minerals are …………………. (Inorganic acids, Weak acids).
\nAnswer:
\nInorganic acids<\/p>\n

\"<\/p>\n

Question 4.
\nAcids turn blue litmus paper to …………….. (green, red, orange).
\nAnswer:
\nRed<\/p>\n

Question 5.
\nSince metal carbonate and metal bicarbonate are basic, they react with acids to give salt and water with the liberation of ……………….. (NO2<\/sub>, SO2<\/sub>, CO2<\/sub>).
\nAnswer:
\nCO2<\/sub><\/p>\n

Question 6.
\nThe hydrated salt of copper sulphate has …………….colour (red, white, blue).
\nAnswer:
\nBlue<\/p>\n

\"<\/p>\n

II. Answer in briefly :<\/span><\/p>\n

Question 1.
\nClassify the various types of Acids based on their sources.
\nAnswer:
\nThe acids are classified based on their sources and organic and inorganic acids.
\nOrganic acids – acids present in plants and animals.
\nInorganic acids – acids prepared from rocks and minerals.<\/p>\n

Question 2.
\nWrite any four uses of acids.
\nAnswer:<\/p>\n

    \n
  • Sulphuric acid is called King of Chemicals because it is used in the preparation of many other compounds. It is used in car batteries also.<\/li>\n
  • Hydrochloric acid is used as a cleansing agent in toilets.<\/li>\n
  • Citric acid is used in the preparation of effervescent salts and as a food preservative.<\/li>\n
  • Nitric acid is used in the manufacture of fertilizers, dyes, paints and drugs.<\/li>\n
  • Oxalic acid is used to clean iron and manganese deposits from quartz crystals. It is also used as bleach for wood and removing black stains.<\/li>\n
  • Carbonic acid is used in aerated drinks.<\/li>\n
  • Tartaric acid is a constituent of baking powder.<\/li>\n<\/ul>\n

    \"<\/p>\n

    Question 3.
    \nGive the significance of pH<\/sup> of .soil in agriculture.
    \nAnswer:
    \nIn agriculture, the pH<\/sup> of soil is very important. Citrus fruits require slightly alkaline soil, while rice requires acidic soil and sugarcane requires neutral soil.<\/p>\n

    Question 4.
    \nWhat are the various uses of Aquaregia.
    \nAnswer:<\/p>\n

      \n
    • It is used chiefly to dissolve metals such as gold and platinum.<\/li>\n
    • It is used for cleaning and refining gold.<\/li>\n<\/ul>\n

      \"<\/p>\n

      Question 5.
      \nWhat are the uses of Plaster of Paris?
      \nAnswer:<\/p>\n

        \n
      • It is used for plastering bones.<\/li>\n
      • It is used for making casts for statues.<\/li>\n<\/ul>\n

        Question 6.
        \nTwo acids \u2018A\u2019 and \u2018B\u2019 are given. Acid A gives one hydrogen ion per molecule of the acid in solution. Acid B gives two hydrogen ions per molecule of the acid in solution.
        \n(i) Find out acid A and acid B.
        \n(ii) Which acid is called the King of Chemicals?
        \nAnswer:
        \n(i) Acid A – HCl – Hydrochloric acid. Acid B – H2<\/sub>SO4<\/sub> – Sulphuric acid.
        \n(ii)Sulphuric acid – H2<\/sub>SO4<\/sub>.<\/p>\n

        \"<\/p>\n

        Question 7.
        \nDefine aquaregia.
        \nAnswer:
        \nIt is the mixture of hydrochloric acid and nitric acid prepared optimally in a molar ratio of 3 : 1.<\/p>\n

        Question 8.
        \nCorrect the mistakes :
        \n(a) Washing soda is used for making cakes and bread soft, spongy.
        \n(b) Calcium sulphate hemihydrate is used in textile industry.
        \nAnswer:
        \n(a) Baking soda (Sodium bicarbonate – NaHCO3<\/sub>) is used for making cakes and bread soft spongy, (or) Washing soda is used for softening hard water.
        \n(b) Calcium sulphate hemihydrate (CaSO4<\/sub>, 1\/2 H2<\/sub>O)is used for plastering bones (or) Bleaching powder (Calcium oxy Chloride – CaOC12<\/sub>) is used in textile industry.<\/p>\n

        \"<\/p>\n

        Question 9.
        \nWhat is neutralization reaction? Give an example.
        \nAnswer:
        \nNeutralization reaction is a reaction in which an acid reacts with a base to form salt and water and H+<\/sup> ion and OH–<\/sup> ion combines to generate water. The neutralization of a strong acid and strong base has a pH<\/sup>equal 7.
        \n\"Samacheer<\/p>\n

        III. Answer in detail :<\/span><\/p>\n

        Question 1.
        \nDifferentiate hydrate and anhydrous salts with examples.
        \nAnswer:<\/p>\n\n\n\n\n\n\n\n\n
        Hydrated<\/td>\nAnhydrous<\/td>\n<\/tr>\n
        1. Hydrons is a term used to explain a substance that contains water as a constituent<\/td>\nAnhydrous is a term used to explain a substance that does not contain water as a constituent.<\/td>\n<\/tr>\n
        2. Composed of water molecules.<\/td>\nNot composed of water molecules.<\/td>\n<\/tr>\n
        3. These are known as hydrates.<\/td>\nKnown as anhydrates<\/td>\n<\/tr>\n
        4. Hydroscopic compounds can form hydrous compounds by Absorption of water from the air.<\/td>\nAnhydrous compounds can absorb water from the air.<\/td>\n<\/tr>\n
        Ex : CuSO4<\/sub> 5H2<\/sub>O – Blue vitrol.<\/td>\nEx: NaCl<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        \"<\/p>\n

        Question 2.
        \nGive the tests to identify Acids and Bases.
        \nAnswer:<\/p>\n

          \n
        • Acids turn blue litmus. Red bases turn red litmus blue.<\/li>\n
        • In acid phenolphthalein is colourless. In base Phenolphthalein is pink in colour.<\/li>\n
        • In acid methyl orange is pink. In bases methyl orange is yellow<\/li>\n<\/ul>\n

          Question 3.
          \nWrite any four uses of bases.
          \nAnswer:<\/p>\n

            \n
          • Sodium hydroxide is used in the manufacture of soap.<\/li>\n
          • Calcium hydroxide is used in the whitewashing of buildings.<\/li>\n
          • Magnesium hydroxide is used as a medicine for a stomach disorder.<\/li>\n
          • Ammonium hydroxide is used to remove grease stains from cloth.<\/li>\n<\/ul>\n

            \"<\/p>\n

            Question 4.
            \nWrite any five uses of salts.
            \nAnswer:
            \nCommon Salt (NaCl) :
            \nIt is used in our daily food and used as a preservative
            \nWashing Soda (Sodium Carbonate – Na2<\/sub>CO3<\/sub>) :<\/p>\n

              \n
            • It is used in softening hard water.<\/li>\n
            • It is used in glass, soap and paper industries.<\/li>\n<\/ul>\n

              Baking Soda (Sodium bicarbonate -NaHCO3<\/sub>):<\/p>\n

                \n
              • It is used in making of baking powder which is a mixture of baking soda and tartaric acid.<\/li>\n
              • It is used in soda-acid fire extinguishers.<\/li>\n
              • Baking powder is used to make cakes and bread, soft and spongy.<\/li>\n
              • It neutralizes excess acid in the stomach and provides relief.<\/li>\n<\/ul>\n

                Bleaching powder (Calcium Oxychloride – CaOCl2<\/sub>):<\/p>\n

                  \n
                • It is used as a disinfectant.<\/li>\n
                • It is used in textile industry for bleaching cotton and linen.<\/li>\n<\/ul>\n

                  Plaster of Paris (Calcium Sulphate Hemihydrate – CaSO4<\/sub> .1\/2 H2<\/sub>O):<\/p>\n

                    \n
                  • It is used for plastering bones<\/li>\n
                  • It is used for making casts for statues.<\/li>\n<\/ul>\n

                    \"<\/p>\n

                    Question 5.
                    \nSulphuric acid is called King of Chemicals. Why is it called so?
                    \nAnswer:
                    \nSulphuric acid is called King of Chemicals because it is used in the preparation of many other compounds<\/p>\n

                    Intext Activities<\/strong><\/p>\n

                    ACTIVITY – 2<\/span><\/p>\n

                    Take solutions of hydrochloric acid or sulphuric acid. Fix two nails on a cork and place the cork in a 100 ml beaker.
                    \nConnect the nails to the two terminals of a 6 V battery through a bulb and a switch as shown in Figure. Now pour some dilute HCl in the beaker and switch on the current. Repeat the activity with dilute sulphuric acid, glucose and alcohol solutions. What do you observe now? Does the bulb glow in all cases?
                    \n\"Samacheer
                    \nAnswer:<\/p>\n

                      \n
                    • The bulb glows when sulphuric acid and hydrochloric acid are used.<\/li>\n
                    • The bulb does not glow when the activity is done with alcohol and glucose solution.<\/li>\n<\/ul>\n

                      \"<\/p>\n

                      ACTIVITY – 3<\/span><\/p>\n

                      Collect the following samples from the science laboratory – Hydrochloric acid, Sulphuric acid and Nitric acid, Sodium hydroxide, Potassium hydroxide. Take 2 ml of each solution in a test tube and test with a litmus paper and indicators phenolphthalein and Methyl orange. Tabulate your observations.
                      \n\"Samacheer
                      \nAnswer:
                      \n\"Samacheer<\/p>\n

                      ACTIVITY-4<\/span>
                      \n\"Samacheer
                      \nAnswer:
                      \n\"Samacheer<\/p>\n

                      ACTIVITY – 5<\/span>
                      \nBoil about 100 ml of groundwater in a vessel to dryness. After all the water get evaporated observe the inner wall of the vessel. Can you observe any deposits? This is the deposit of dissolved salts present in water.
                      \nAnswer:
                      \nThis is the deposit of dissolved salts present in water.<\/p>\n

                      \"<\/p>\n

                      9th Science Guide Acids, Bases and Salts Additional Important Questions and Answers<\/h3>\n

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

                      Question 1.
                      \nAcid secreted in our stomach is ……………….
                      \n(a) hydrochloric acid
                      \n(b) sulphuric acid
                      \n(c) nitric acid
                      \n(d) carbonic acid
                      \nAnswer:
                      \n(a) hydrochloric acid<\/p>\n

                      Question 2.
                      \nHydrochloric Acid reacts with metal bicarbonates to give ……………
                      \n(a) metal chloride
                      \n(b) water
                      \n(c) carbon di – oxide
                      \n(d) all the above
                      \nAnswer:
                      \n(d) all the above<\/p>\n

                      \"<\/p>\n

                      Question 3.
                      \n…………… & ………….. metals do not react with HCl or HNO3<\/sub>.
                      \n(a) Gold & Magnesium
                      \n(b) Silver & Magnesium
                      \n(c) Gold & Silver
                      \n(d) Zinc & Silver
                      \nAnswer:
                      \n(c) Gold & Silver<\/p>\n

                      Question 4.
                      \nThe molar ratio of hydrochloric acid and nitric acid in aquaregia is ………………..
                      \n(a) 1 : 3
                      \n(b) 6 : 3
                      \n(c) 2 : 3
                      \n(d) 3 : 1
                      \nAnswer:
                      \n(d) 3 : 1<\/p>\n

                      \"<\/p>\n

                      Question 5.
                      \nBases ionise in water to form ……………………. ions.
                      \n(a) H+<\/sup>
                      \n(b) H3<\/sub>O+<\/sup>
                      \n(c) OH–<\/sup>
                      \n(d) O2-<\/sup>
                      \nAnswer:
                      \n(c) OH –<\/sup><\/p>\n

                      Question 6.
                      \nWhich of the following pairs are weak base?
                      \n(a) NH4<\/sub>OH & NaOH ‘
                      \n(b) Ca(OH)2<\/sub> & KOH
                      \n(c) NH4<\/sub>OH & Ca(OH)2<\/sub>
                      \n(d) NaOH&KOH
                      \nAnswer:
                      \n(c) NH4<\/sub>OH & Ca(OH)2<\/sub><\/p>\n

                      \"<\/p>\n

                      Question 7.
                      \nNaOH & KOH are …………….
                      \n(a) strong bases
                      \n(b) metal Oxides
                      \n(c) weak bases
                      \n(d) diacidic bases
                      \nAnswer:
                      \n(a) strong bases<\/p>\n

                      Question 8.
                      \nWhich of the following solution is soapy to touch?
                      \n(a) Acidic
                      \n(b) Basic
                      \n(c) Salt
                      \n(a(d) Aquaregia
                      \nAnswer:
                      \n(b) Basic<\/p>\n

                      \"<\/p>\n

                      Question 9.
                      \nWhich of the following solutions do not conduct electricity?
                      \n(a) alcohol
                      \n(b) glucose
                      \n(c) sulphuric acid
                      \n(d) both a & b
                      \nAnswer:
                      \n(d) both a & b<\/p>\n

                      Question 10.
                      \nThe pH<\/sup> value of neutral solution is ………………
                      \n(a) = 7
                      \n(b) <7
                      \n(c) none of the above
                      \n(d) -7
                      \nAnswer:
                      \n(a) = 7<\/p>\n

                      \"<\/p>\n

                      Question 11.
                      \nThe pH<\/sup> of stomach fluid is ……………….
                      \n(a) 4
                      \n(b) 2
                      \n(c) 6
                      \n(d) 7
                      \nAnswer:
                      \n(b) 2<\/p>\n

                      Question 12.
                      \nA salt which is formed by complete neutralization of an acid and a base is called ………………. salt.
                      \n(a) basic
                      \n(b) acid
                      \n(c) double
                      \n(d) normal
                      \nAnswer:
                      \n(d) normal<\/p>\n

                      \"<\/p>\n

                      Question 13.
                      \nThe number of water molecules present in one molecule of copper sulphate is
                      \n(a) 2
                      \n(b) 3
                      \n(c) 4
                      \n(d) 5
                      \nAnswer:
                      \n(d) 5<\/p>\n

                      Question 14.
                      \nThe molecular formula of copper sulphate pentahydrate is ………………..
                      \n(a) CuSO4<\/sub>. H2<\/sub>O
                      \n(b) CuSO4<\/sub>. 2H2<\/sub>O
                      \n(c) CuSO4<\/sub>. 5H2<\/sub>O
                      \n(d) CuSO4<\/sub>. 3H2<\/sub>O
                      \nAnswer:
                      \n(c) CuSO4<\/sub> . 5H2<\/sub>O<\/p>\n

                      \"<\/p>\n

                      Question 15.
                      \n……………is the gas produced when HCl is added with carbonate salt.
                      \n(a) H2<\/sub>
                      \n(b) N2<\/sub>
                      \n(C) CO2<\/sub>
                      \n(d) O2<\/sub>
                      \nAnswer:
                      \n(c)CO2<\/sub><\/p>\n

                      Question 16.
                      \nThe formula of bleaching powder is ……………..
                      \n(a) CaCl2<\/sub>
                      \n(b) CaOCl2<\/sub>
                      \n(c) Ca(OH)2<\/sub>
                      \n(d) CaO
                      \nAnswer:
                      \n(b) CaOCl2<\/sub><\/p>\n

                      \"<\/p>\n

                      Question 17.
                      \nThe chemical name of plaster of paris is ……………………..
                      \n(a) Calcium sulphate hemihydrate
                      \n(b) Calcium sulphate monohydrate
                      \n(c) Calcium sulphate dihydrate
                      \n(d) Calcium sulphate trihydrate
                      \nAnswer:
                      \n(a) Calcium sulphate hemihydrate<\/p>\n

                      Question 18.
                      \nWhich of the following metal does not react with sodium hydroxides?
                      \n(a) Cu
                      \n(b) Ag
                      \n(c) Cr
                      \n(d) All the above
                      \nAnswer:
                      \n(d) All the above<\/p>\n

                      \"<\/p>\n

                      Question 19.
                      \nCurd contains …………….acid.
                      \n(a) malic ‘
                      \n(b) formic
                      \n(c) lactic
                      \n(d) ascorbic
                      \nAnswer:
                      \n(c) lactic<\/p>\n

                      Question 20.
                      \nWhich one of the following acids undergoes complete ionisation?.
                      \n(a) HCl
                      \n(b) CH3<\/sub>COOH
                      \n(c) H2<\/sub>SO4<\/sub>
                      \n(d) all the above
                      \nAnswer:
                      \n(a) HCl<\/p>\n

                      \"<\/p>\n

                      II. Fill in the blanks :<\/span><\/p>\n

                      1. Acid reacts with base to form a neutral product called ………………
                      \nAnswer:
                      \nSalt<\/p>\n

                      2. The taste of acid is ………………..
                      \nAnswer:
                      \nSour<\/p>\n

                      3. …………….. contain one or more replaceable hydrogen atoms.
                      \nAnswer:
                      \nAcids<\/p>\n

                      \"<\/p>\n

                      4. ………………..acids have a relatively smaller amount of acids dissolved in a solvent.
                      \nAnswer:
                      \nDilute<\/p>\n

                      5. Acids react with metallic oxides to produce ……………….
                      \nAnswer:
                      \nsalt and water<\/p>\n

                      6. _________ acid is used in aerated drinks.
                      \nAnswer:
                      \nCarbonic acid<\/p>\n

                      \"<\/p>\n

                      7. Chemical formula of aquaregia is ________
                      \nAnswer:
                      \n3HCl + HNO3<\/sub><\/p>\n

                      8. Water soluble bases are called ________
                      \nAnswer:
                      \nalkali<\/p>\n

                      9. Non-metallic oxides are ___________ in nature.
                      \nAnswer:
                      \nacid<\/p>\n

                      \"<\/p>\n

                      10. __________ are bitter in taste.
                      \nAnswer:
                      \nBases<\/p>\n

                      11. __________ alkali has a relatively high percentage of alkali in its aqueous solution.
                      \nAnswer:
                      \nConcentrated<\/p>\n

                      12. Acids turn blue litmus to ………….
                      \nAnswer:
                      \nred<\/p>\n

                      \"<\/p>\n

                      13. Phenolphthalein and methyl Orange are ………………
                      \nAnswer:
                      \nindicators<\/p>\n

                      14. pH<\/sup> stands for …………….. in a solution.
                      \nAnswer:
                      \npower of hydrogen ion concentration<\/p>\n

                      15. The pH<\/sup> value of acids are …………….. than 7.
                      \nAnswer:
                      \nlesser<\/p>\n

                      \"<\/p>\n

                      16. White enamel coating of our teeth is…………….
                      \nAnswer:
                      \nCalcium phosphate<\/p>\n

                      17. Salt is ………….. in nature.
                      \nAnswer:
                      \nhygroscopic<\/p>\n

                      18. Salt which is formed by the partial replacement of hydrogen ions of an acid by a metal is called ………………………..
                      \nAnswer:
                      \nacid salt<\/p>\n

                      \"<\/p>\n

                      19 Salts conta\u00edning water of crystallisation are called …………. salts.
                      \nAnswer:
                      \nhydrated<\/p>\n

                      20. Salts that do not contain water of crystallisation is called …………..
                      \nAnswer:
                      \nanhydrous salt<\/p>\n

                      21. pH<\/sup> value of human blood is ……………..(7.0, 7.4, 7.6).
                      \nAnswer:
                      \n7.4<\/p>\n

                      \"<\/p>\n

                      22. The nature of the toothpaste commonly used is ……………. in nature (acidic, basic, neutral)
                      \nAnswer:
                      \nbasic<\/p>\n

                      23. You are given pure water to test the pH<\/sup> value using pH<\/sup> paper. It shows colour (White, black, green)
                      \nAnswer:
                      \ngreen<\/p>\n

                      III. To Match:<\/span><\/p>\n

                      Question 1.<\/p>\n\n\n\n\n\n\n\n\n
                      Source<\/td>\nAcid present<\/td>\n<\/tr>\n
                      1) Apple<\/td>\n?<\/td>\n<\/tr>\n
                      2) ?<\/td>\nCitric acid<\/td>\n<\/tr>\n
                      3) ?<\/td>\ntartaric acid<\/td>\n<\/tr>\n
                      4) Tomato<\/td>\n?<\/td>\n<\/tr>\n
                      5) Vinegar<\/td>\n?<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:<\/p>\n\n\n\n\n\n\n\n\n
                      Source<\/td>\nAcid present<\/td>\n<\/tr>\n
                      1) Apple<\/td>\nMalic acid<\/td>\n<\/tr>\n
                      2) Lemon<\/td>\nCitric acid<\/td>\n<\/tr>\n
                      3) Grapes<\/td>\ntartaric acid<\/td>\n<\/tr>\n
                      4) Tomato<\/td>\nOxalic acid<\/td>\n<\/tr>\n
                      5) Vinegar<\/td>\nAcetic acid<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      \"<\/p>\n

                      Question 2.
                      \n\"Samacheer<\/p>\n

                      Answer:
                      \n\"Samacheer<\/p>\n

                      Question 3.
                      \n\"Samacheer
                      \nAnswer:
                      \n\"Samacheer<\/p>\n

                      Question 4.
                      \n\"Samacheer
                      \nAnswer:
                      \n\"Samacheer<\/p>\n

                      IV. Complete the following equations.<\/span><\/p>\n

                      Question 1.
                      \nHCl + H2<\/sub>O \u2192 ? + ?
                      \nAnswer:
                      \nHCl + H2<\/sub>O \u2192 H3<\/sub>O+<\/sup> + Cl–<\/sup><\/p>\n

                      \"<\/p>\n

                      Question 2.
                      \nH+<\/sup> + H2<\/sub>O \u2192 ?
                      \nAnswer:
                      \nH+<\/sup> + H2<\/sub>O \u2192 H3<\/sub>O+<\/sup><\/p>\n

                      Question 3.
                      \nMg+ ? \u2192 ? + H2<\/sub>
                      \nAnswer:
                      \nMg + H2<\/sub>SO4<\/sub> \u2192 MgSO4<\/sub> + H2<\/sub>\u2191<\/p>\n

                      Question 4.
                      \nNa2<\/sub>CO3<\/sub> + 2HCl \u2192 ? + ? + CO2<\/sub>\u2191
                      \nAnswer: Na2<\/sub>CO3<\/sub> + 2HCl \u2192 2NaCl + H2<\/sub>O + CO2<\/sub>\u2191<\/p>\n

                      \"<\/p>\n

                      Question 5.
                      \nZnO + 2HCl \u2192 ? + ?
                      \nAnswer:
                      \nZnO + 2HCl \u2192 ZnCl2<\/sub> + H2<\/sub>O\u2191<\/p>\n

                      Question 6.
                      \nZn + ? \u2192 Na2<\/sub>ZnO2<\/sub> + H2<\/sub> \u2191
                      \nAnswer:
                      \nZn + 2NaOH \u2192 Na2<\/sub>ZnO2<\/sub>+ H2<\/sub>\u2191<\/p>\n

                      Question 7.
                      \nCaO + H2<\/sub>SO4<\/sub> \u2192 ? + H2<\/sub>O
                      \nAnswer:
                      \nCaO + H2<\/sub>SO4 <\/sub> \u2192 CaSO4<\/sub> + H2<\/sub>O<\/p>\n

                      \"<\/p>\n

                      Question 8.
                      \nHCl + ? \u2192 NaCl + H2<\/sub>O
                      \nAnswer:
                      \nHCl + NaOH \u2192 NaCl + H2<\/sub>O<\/p>\n

                      Question 9.
                      \nCa(OH)2<\/sub> + ? \u2192 ? + H2<\/sub>O
                      \nAnswer:
                      \nCa(OH)2<\/sub> + CO2<\/sub> \u2192 CaCO3<\/sub> + H2<\/sub>O<\/p>\n

                      Question 10.
                      \n\"Samacheer
                      \nAnswer:
                      \nA = NH4<\/sub>Cl, B = NH3<\/sub>\u2191
                      \nC = HCl
                      \nD = NaHSO4<\/sub>,E = H2<\/sub>O<\/p>\n

                      V. Answer in briefly :<\/span><\/p>\n

                      Question 1.
                      \nWhat are organic acids? Given examples.
                      \nAnswer:
                      \nAcids present in plants and animals (living things) are organic acids.
                      \nExample: HCOOH, CH3<\/sub>COOH<\/p>\n

                      \"<\/p>\n

                      Question 2.
                      \nHow are acids classified based on ionisation? Give examples.
                      \nAnswer:
                      \nAcids get ionise in water (produce H+<\/sup> ions) completely or partially. Based on the extent of ionisation, acids are classified as follows:
                      \nStrong Acids:
                      \nThese are acids that ionise completely in water.
                      \nExample: HCl<\/p>\n

                      Weak Acids :
                      \nThese are acids that ionise partially in the water.
                      \nExample: CH3<\/sub>COOH.<\/p>\n

                      Question 3.
                      \nWhat is Aquaregia? Mention its uses.
                      \nAnswer:
                      \nIt is a mixture of hydrochloric acid and nitric acid prepared optimally in a molar ratio of 3:1. It is a yellow-orange fuming liquid. It is a highly corrosive liquid, able to attack gold and other resistant substances.<\/p>\n

                        \n
                      • Aquaregia is used tp dissolve noble metals such as gold, platinum, and palladium.<\/li>\n
                      • It is used Tor cleaning and refining gold.<\/li>\n<\/ul>\n

                        Question 4.
                        \nWhat does the acidity of base mean?
                        \nAnswer:
                        \nIt means the number of replaceable hydroxyl groups present in one molecule of a base.<\/p>\n

                        \"<\/p>\n

                        Question 5.
                        \nWhat is Potash alum? Write its formula.
                        \nAnswer:
                        \nPotash alum is a mixture of potassium sulphate and aluminium sulphate. KAl(SO4<\/sub>)2<\/sub>.12H2<\/sub>O.<\/p>\n

                        Question 6.
                        \nWhat are double salts? Give an example?
                        \nAnswer:
                        \nDouble salts are the salts formed by the combination of the saturated solution of two simple salts in equimolar ratio followed by crystallization. For example : Potash alum.<\/p>\n

                        Question 7.
                        \nWhat are basic salts? Give suitable reaction for this.
                        \nAnswer:
                        \nBasic salts are the product formed by the partial replacement of hydroxide ions of a diacidic or triacidic base with an acid radical.
                        \nPb(OH)2<\/sub> + HCl \u2192 Pb(OH)Cl + H2<\/sub>O<\/p>\n

                        \"<\/p>\n

                        Question 8.
                        \nWhy are tooth pastes basic?
                        \nAnswer:
                        \nToothpastes which are generally basic and used for cleaning the teeth can neutralise the excess acid and prevent tooth decay.<\/p>\n

                        Question 9.
                        \nWhat is water of crystallisation?
                        \nAnswer:
                        \nMany salts are found as crystals with water molecules they contain. These water molecules are known as water of crystallisation.<\/p>\n

                        \"<\/p>\n

                        Question 10.
                        \nWhy do blue colour copper sulphate becomes white on heating?
                        \nAnswer:
                        \nOn heating, blue colour copper sulphate loses its water molecules and becomes white.<\/p>\n

                        Question 11.
                        \nAcidic or basic solutions are good conductors of electricity. Justify your answer.
                        \nAnswer:
                        \nAcidic and basic solutions in water conduct electricity because they produce hydrogen and hydroxide ions respectively.<\/p>\n

                        \"<\/p>\n

                        Question 12.
                        \nWhat are hygroscopic substances?
                        \nAnswer:
                        \nSubstance which absorbs water from the surroundings are called hygroscopic substances.<\/p>\n

                        Question 13.
                        \nDefine indicator. Give examples
                        \nAnswer:
                        \nChemical substances used to find out whether the given solution is acid or base are called indicators. Eg: Phenolphthalein, methyl orange.<\/p>\n

                        \"<\/p>\n

                        Question 14.
                        \nDefine ionisation.
                        \nAnswer:
                        \nIonisation is the condition of being dissociated into ions by heat or radiation or chemical reactions or electrical discharge.<\/p>\n

                        Question 15.
                        \nHow is normal salt obtained? Give a suitable reaction.
                        \nAnswer:
                        \nA normal salt is obtained by complete neutralization of an acid by a base.
                        \nNaOH + HCl \u2192 NaCl + H2<\/sub>O<\/p>\n

                        Question 16.
                        \nHow are bases classified based on ionisation?
                        \nAnswer:
                        \nBased on Ionisation
                        \n(a) Strong Bases :
                        \nThese are bases which ionise completely in aqueous solution.
                        \nExample: NaOH, KOH<\/p>\n

                        (b) Weak Bases:
                        \nThese are bases that ionise partially in aqueous solution.
                        \nExample: NH4<\/sub>OH, Ca(OH)2<\/sub><\/p>\n

                        \"<\/p>\n

                        VI. To Interpret:<\/span><\/p>\n

                        Question 1.
                        \nCH4<\/sub> and NH3<\/sub>, are not acids.
                        \nAnswer:
                        \nCH4<\/sub> and NH3<\/sub> do not produce hydrogen ion (H+<\/sup>) in its aqueous solution.<\/p>\n

                        Question 2.
                        \nAcetic acid (CH3<\/sub>COOH) is a mono basic acid.
                        \nAnswer:
                        \nThough acetic acid contains four hydrogen atoms only one hydrogen can be replaced in its aqueous solution. So CH3<\/sub>COOH is a mono basic acid.
                        \nCH3<\/sub>COOH \u2192 H+<\/sup>+ + CH3<\/sub>COO–<\/sup><\/p>\n

                        \"<\/p>\n

                        Question 3.
                        \nAl(OH)3<\/sub> & Zn(OH)2<\/sub> are not alkalis.
                        \nAnswer:
                        \nAl(OH)3<\/sub> & Zn(OH)2<\/sub> are water insoluble bases. So they are bases not alkalies.<\/p>\n

                        Question 4.
                        \nNaOH & KOH are strong bases.
                        \nAnswer:
                        \nThese are bases which ionise completely in aqueous solution.<\/p>\n

                        Question 5.
                        \nNaHSO4<\/sub> is an acid salt.
                        \nAnswer:
                        \nIt is formed by the partial replacement of hydrogen ion of sulphuric acid (H2<\/sub> SO4<\/sub> ) by a metal present in sodium hydroxide (NaOH).
                        \nNaOH + H2<\/sub> SO4<\/sub> \u2192 NaHSO4<\/sub> + H2<\/sub>O<\/p>\n

                        \"<\/p>\n

                        Question 6.
                        \nNon-metallic oxides are acidic is nature.
                        \nAnswer:
                        \nWhen non – metallic oxides react with bases, they can form a salt and water similar to the reaction of base with acids. So non-metallic oxides are acidic in nature.
                        \n\"Samacheer<\/p>\n

                        VII. Complete the following table:<\/span><\/p>\n

                        Question 1.
                        \n\"Samacheer
                        \nAnswer:
                        \n\"Samacheer<\/p>\n

                        Question 2.
                        \n\"Samacheer
                        \nAnswer:
                        \n\"Samacheer<\/p>\n

                        Question 3.<\/p>\n\n\n\n\n\n\n\n\n
                        1) Hydrochloric acid<\/td>\na) Fertilizer<\/td>\n<\/tr>\n
                        2) Citric acid<\/td>\nb) Baking powder<\/td>\n<\/tr>\n
                        3) Nitric acid<\/td>\nc) Car batteries<\/td>\n<\/tr>\n
                        4) Oxalic acid<\/td>\nd) Cleansing agent in toilets<\/td>\n<\/tr>\n
                        5) Sulphuric acid<\/td>\ne) Removing black stains<\/td>\n<\/tr>\n
                        <\/td>\nf) Effervescent salts<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                        Answer:
                        \n1. – d, 2. – f, 3. – a, 4. – e, 5. – c<\/p>\n

                        Question 4.<\/p>\n\n\n\n\n\n\n\n\n
                        1) Hardest substance in our body<\/td>\na) Aluminium phosphate<\/td>\n<\/tr>\n
                        2) Citrus fruits<\/td>\nb) Potash alum<\/td>\n<\/tr>\n
                        3) Rice plant<\/td>\nc) Insoluble in water<\/td>\n<\/tr>\n
                        4) Double salts<\/td>\nd) Acidic soil<\/td>\n<\/tr>\n
                        5) Silver chloride<\/td>\ne) Calcium phophate<\/td>\n<\/tr>\n
                        <\/td>\nf) Alkaline soil<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                        Answer:
                        \nl.-e,2.-f,3.-d,4-b,5.-c<\/p>\n

                        VIII. Find odd one out & give reason :<\/span><\/p>\n

                        Question 1.
                        \nHCl, HNO3<\/sub>, HCOOH, H3<\/sub>PO4<\/sub>
                        \nAnswer:
                        \nH3<\/sub>PO4<\/sub>,
                        \nIt is a tribasic acid whereas other three are monobasic acids.<\/p>\n

                        Question 2.
                        \nAcetic acid, formic acid, tartaric acid, sulphuric acid.
                        \nAnswer:
                        \nSulphuric acid.
                        \nIt is a mineral acid whereas other three are organic acids.<\/p>\n

                        \"<\/p>\n

                        Question 3.
                        \nCaO, Na2<\/sub>O, ZnO, NaOH
                        \nAnswer:
                        \nNaOH.
                        \nIt is a base containing replaceable hydroxyl ion. whereas other three bases contain replaceable oxide ions.<\/p>\n

                        Question 4.
                        \nBitter taste, soupy to touch, turns red litmus to blue, produce pink colour with methyl orange.
                        \nAnswer:
                        \nProduce pink colour with methyl orange.
                        \nIt is the property of acids whereas other three are properties of bases.<\/p>\n

                        \"<\/p>\n

                        Question 5.
                        \nLitmus paper, phenolphthalein, methyl orange, Aquaregia.
                        \nAnswer:
                        \nAquaregia.
                        \nIt is a mixture of two acids namely, hydrochloric acid and nitric acid, used to dissolve metals such as gold and platinum whereas other three are indicators used to identify the nature of the solution.<\/p>\n

                        IX. Spot the error \/ Correct the wrong statement given below :<\/span><\/p>\n

                        Question 1.
                        \nAn acid is the compound which are capable of forming hydroxyl ions (OH–<\/sup> ) in aqueous solution. .
                        \nAnswer:
                        \nAn acid is the compound which are capable of forming hydrogen ions (H+) in aqueous , solution, (or) A base is the compound which are capable of forming hydroxyl ion (OH-) in aqueous solution.<\/p>\n

                        \"<\/p>\n

                        Question 2.
                        \nNitric Acid is a constituent of baking powder.
                        \nAnswer:
                        \nTartaric acid is a constituent of baking powder.<\/p>\n

                        Question 3.
                        \nThe pH<\/sup> value of the base in lesser than 7.
                        \nAnswer:
                        \nThe pH<\/sup> value of the base is greater than 7. (or) pH<\/sup> value of an acid is lesser than 7.<\/p>\n

                        Question 4.
                        \nCa(OH)2<\/sub> is a triacidic base.
                        \nAnswer:
                        \nCa(OH)2<\/sub> is a diacidic base (or) Al(OH)3<\/sub> is a triacidic base.<\/p>\n

                        \"<\/p>\n

                        Question 5.
                        \nMagnesium hydroxide is used in whitewashing of buildings.
                        \nAnswer:
                        \nMagnesium hydroxide is used as an antacid. (or) Calcium hydroxide is used in whitewashing of buildings.<\/p>\n

                        X. Answer in detail :<\/span><\/p>\n

                        Question 1.
                        \nExplain the classification of acids based on their basicity.
                        \nAnswer:
                        \nMonobasic Acid :
                        \nAcid that contain only one replaceable hydrogen atom per molecule is called monobasic acid. It gives one hydrogen ion per molecule of the acid in solutions.
                        \nExample: HCl, HNO3<\/sub>
                        \n.
                        \nDibasic Acid :
                        \nAn acid which gives two hydrogen ions per molecule of the acid in solution.
                        \nExample : H2<\/sub>SO4<\/sub>, H2<\/sub>CO3<\/sub>
                        \n‘
                        \nTribasic Acid :
                        \nAn acid which gives three hydrogen ions per molecule of the acid in solution.
                        \nExample: H3<\/sub>PO4<\/sub>.<\/p>\n

                        \"<\/p>\n

                        Question 2.
                        \nWrite notes on the properties of acids.
                        \nAnswer:
                        \n(a) They have sour taste.
                        \n(b) Their aqueous solutions conduct electricity since they contain ions
                        \n(c) Acids turns blue litmus red.
                        \n(d) Acids react with active metals to give hydrogen gas.
                        \nMg + H2<\/sub>SO4<\/sub> \u2192 MgSO4<\/sub> + H 2<\/sub>\u2191
                        \nZn + 2HCl \u2192 ZnCl2<\/sub> + H2<\/sub>\u2191<\/p>\n

                        (e) Acids react with metal carbonate and metal hydrogen carbonate to give carbon dioxide.
                        \nNa2<\/sub>CO3<\/sub> + 2HCl \u2192 2NaCl + H2<\/sub>O + CO2<\/sub>\u2191
                        \nNaHCO3<\/sub> + HCl \u2192 NaCl + H2<\/sub>O + CO2<\/sub>\u2191<\/p>\n

                        (f) Acids react with metallic oxides to give salt and water.
                        \nCaO + H2<\/sub>SO4<\/sub> \u2192 CaSO4<\/sub>+ H2<\/sub>O<\/p>\n

                        (g) Acids react with bases to give salt and water.
                        \nHCl + NaOH \u2192 NaCl + H2<\/sub>O.<\/p>\n

                        Question 3.
                        \nWrite notes on the properties of bases. .
                        \nAnswer:
                        \n(a) They have bitter taste.
                        \n(b) Their aqueous solutions have soapy touch.
                        \n(c) They turn red litmus blue.
                        \n(d)Their aqueous solutions conduct electricity.
                        \n(e) Bases react with metals to form salt with the liberation of hydrogen gas.
                        \nZn + 2 NaOH \u2192 Na2<\/sub>ZnO2<\/sub> + H2<\/sub>\u2191<\/p>\n

                        (f) Bases react with non-metallic oxides to produce salt and water. Since this is similar to the reaction between a base and an acid, we can conclude that non-metallic oxides are acidic in nature,
                        \nCa(OH)2<\/sub> + CO2<\/sub> \u2192 CaCO3<\/sub>+ H2<\/sub>O<\/p>\n

                        (g) Bases react with acids to form salt and water.
                        \nKOH + HCl \u2192 KCl + H2<\/sub>O
                        \nThe above reaction between a base and an acid is known as Neutralisation reaction.<\/p>\n

                        (h) On heating with ammonium salts, bases give ammonia gas.
                        \nNaOH + NH4<\/sub>Cl \u2192 NaCl + H2<\/sub>O+ NH3<\/sub>\u2191<\/p>\n

                        \"<\/p>\n

                        Question 4.
                        \nDescribe the classification of bases based on their acidity.
                        \nAnswer:
                        \n(a) Monoacidic Base :
                        \nIt is a base that ionises in water to give one hydroxide ion per molecule.
                        \nExample: NaOH, KOH<\/p>\n

                        (b) Diacidic Base:
                        \nIt is a base that ionises in water to give two hydroxide ions per molecule.
                        \nExample: Ca(OH)2<\/sub>, Mg(OH)2<\/sub><\/p>\n

                        (c) Triacidic Base :
                        \nIt is a base that ionises in water to give three hydroxide ions per molecule.
                        \nExample: Al(OH)3<\/sub>, Fe(OH)3<\/sub><\/p>\n

                        Question 5.
                        \nWrite notes on importance of pH in everyday life.
                        \nAnswer:
                        \npH<\/sup> in our digestive system :
                        \nHydrochloric acid produced in our stomach helps in the digestion of food without harming the stomach. During indigestion, the stomach produces too much acid and this causes pain and irritation. pH of stomach fluid is approximately 2.0<\/p>\n

                        pH<\/sup> changes is the cause of tooth decay :
                        \nWhite enamel coating of our teeth is calcium phosphate, the hardest substance in our body. Toothpaste which are generally basic and used for cleaning the teeth can neutralise the excess acid and prevent tooth decay.<\/p>\n

                        pH<\/sup> of soil:
                        \nIn agriculture, the pH of soil is very important. Citrus fruits require slightly alkaline soil, while rice requires acidic soil and sugarcane requires neutral soil.<\/p>\n

                        pH<\/sup> of rain water:
                        \nThe pH of rainwater is approximately 7 which means that it is neutral and also represents its high purity. If the atmospheric air is polluted with oxides of sulphur and nitrogen, they get dissolved in rainwater and make its pH less than 7. Thus, if the pH of rainwater is less than 7, then it is called acid rain. When acid rain flows into the rivers it lowers the pH of the river water. The survival of aquatic life in such rivers becomes difficult.<\/p>\n

                        \"<\/p>\n

                        Question 6.
                        \nList the properties of salts.
                        \nAnswer:<\/p>\n

                          \n
                        • \u00a0Salts are mostly solids which melt as well as boil at high temperature.<\/li>\n
                        • Most of the salts are soluble in water.
                          \nFor example, chloride salts of potassium and sodium are soluble in water. But silver chloride is insoluble in water.<\/li>\n
                        • They are odourless, mostly white, cubic crystals or crystalline powder with a salty taste.<\/li>\n
                        • Salt is hygroscopic in nature.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                          Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 14 Acids, Bases and Salts Text Book Back Questions and Answers, Notes. Samacheer Kalvi 9th Science Solutions Chapter 14 Acids, Bases and Salts 9th Science Guide Acids, Bases and Salts Text Book Back Questions and Answers I. Choose the correct answer : Question …<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-23850","post","type-post","status-publish","format-standard","hentry","category-class-9"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/23850"}],"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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/comments?post=23850"}],"version-history":[{"count":1,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/23850\/revisions"}],"predecessor-version":[{"id":41259,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/posts\/23850\/revisions\/41259"}],"wp:attachment":[{"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/media?parent=23850"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/categories?post=23850"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/samacheerkalvi.guide\/wp-json\/wp\/v2\/tags?post=23850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}