Chapter 2

Acids, Bases and Salts

āĻāϚিāĻĄ, āφāϧাā§° āφ⧰ু āĻ˛ā§ąāĻŖ

EXERCISES.

āĻŦ্āϝাāϝ়াāĻŽ।

 1. A solution turns red litmus blue, its ph. is likely to be

 ā§§. āĻāϟা āĻĻ্ā§°ā§ąāĻŖ ā§°āĻ™া āϞিāϟāĻŽাāĻ› āύীāϞা āĻšৈ āĻĒā§°ে, āχāϝ়াā§° āĻĒিāĻāχāϚ āĻšোā§ąাā§° āϏāĻŽ্āĻ­াā§ąāύা āφāĻ›ে

 (a) I                  (b) 4

(c) 5                   (d) 10

 (āĻ•) āφāχ     (āĻ–) ā§Ē

(āĻ—) ā§Ģ     (āϘ) ā§§ā§Ļ

 Ans-


2. A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains

⧍. āĻāϟা āĻĻ্ā§°ā§ąāĻŖে āĻ—ুā§°ি āϕ⧰া āĻ•āĻŖীā§° āĻ–োāϞাā§° āϏৈāϤে āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āϕ⧰ি āϚূāĻŖ-āĻĒাāύীā§° āĻĻুāĻ—্āϧāĻ—ā§°্āĻ­ āϤৈāϝ়াā§° āϕ⧰া āĻ—েāĻ› āĻāϟা āĻĻিāϝ়ে। āĻĻ্ā§°ā§ąāĻŖāϤ āφāĻ›ে

 (a) NaCl            (b) HCI

 (c) LICI              (d) KCI

(āĻ•) āĻāύāĻāϚিāĻāϞ     (āĻ–) āĻāχāϚāϚিāφāχ

(āĻ—) āĻāϞāφāχāϚিāφāχ     (āϘ) āĻ•েāϚিāφāχ

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3. 10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount HCI solution (the same solution as before) required to neutralise it will be

ā§Š. āύাāĻ“āĻāχāϚ-ā§° āĻĻ্ā§°ā§ąāĻŖā§° 10 āĻŽিāϞি āĻāχāϚāϚিāĻāϞ-ā§° āĻāϟা āύিā§°্āĻĻিāώ্āϟ āĻĻ্ā§°ā§ąāĻŖā§° 8 āĻŽিāϞিā§° āĻĻ্āĻŦাā§°া āϏāĻŽ্āĻĒূā§°্āĻŖā§°ূāĻĒে āύিāώ্āĻ•্ā§°িāϝ় āĻšোā§ąা āĻĻেāĻ–া āϝাāϝ়। āϝāĻĻি āφāĻŽি āύাāĻ“āĻšā§° āĻāĻ•েāĻĻ্ā§°ā§° 20 āĻŽিāϞি āϞāĻ“ঁ, āχāϝ়াāĻ• āύিāώ্āĻ•্ā§°িāϝ় āϕ⧰িāĻŦāϞৈ āĻĒ্ā§°āϝ়োāϜāύীāϝ় āĻĒā§°িāĻŽাāĻŖ āĻāχāϚāϚিāφāχ āϏāĻŽাāϧাāύ (āφāĻ—ā§° āĻĻā§°ে āĻāĻ•ে āϏāĻŽাāϧাāύ) āĻš'āĻŦ

 (a) 4 mL             (b) 8 mL

 (c) 12 mL           (d) 16 mL

 (āĻ•) 4 āĻŽিāϞি (āĻ–) 8 āĻŽিāϞি

(āĻ—) 12 āĻŽিāϞি (āϘ) 16 āĻŽিāϞি

  Ans-


4. Which one of the following types of medicines is used for treating indigestion?

ā§Ē. āĻŦāĻĻāĻšāϜāĻŽā§° āϚিāĻ•িā§ŽāϏাā§° āĻŦাāĻŦে āύিāĻŽ্āύāϞিāĻ–িāϤ āĻ•োāύ āĻĒ্ā§°āĻ•াā§°ā§° āĻ”āώāϧ āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰া āĻšāϝ়?

 (a) Antibiotic     (b) Analgesic

 (c) Antacid         (d) Antiseptic

 (āĻ•) āĻāĻŖ্āϟিāĻŦাāϝ়āϟিāĻ• (āĻ–) āĻāύাāϞāϜেāϚিāĻ•

(āĻ—) āĻāĻŖ্āϟাāϚিāĻĄ (āϘ) āĻāĻŖ্āϟিāϚেāĻĒ্āϟিāĻ•

  Ans-


5. Write word equations and then balanced equations for the reaction taking place when -

ā§Ģ. āĻļāĻŦ্āĻĻ āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ• āφ⧰ু āϤাā§° āĻĒিāĻ›āϤ āĻ•েāϤিāϝ়া āĻšোā§ąা āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻŦাāĻŦে āϏāύ্āϤুāϞিāϤ āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ• -

 (a) dilute sulphuric acid reacts with zinc granules.

 (āĻ•) āĻĒাāϤāϞ āĻ›াāϞāĻĢিāω⧰িāĻ• āĻāϚিāĻĄে āϜিংāĻ• āĻĻাāύাā§°ে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ে।

 (b) dilute hydrochloric acid reacts with magnesium ribbon.

 (āĻ–) āĻĒাāϤāϞ āĻšাāχāĻĄ্ā§°āĻ•্āϞ'ā§°িāĻ• āĻāϚিāĻĄে āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ ā§°িāĻŦāύ⧰ āϏৈāϤে āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āϕ⧰ে।

 (c) dilute sulphuric acid reacts with aluminium powder.

 (āĻ—) āĻĒাāϤāϞ āĻ›াāϞāĻĢিāω⧰িāĻ• āĻāϚিāĻĄে āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻĒাāωāĻĄাā§°ā§° āϏৈāϤে āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āϕ⧰ে।

 (d) dilute hydrochloric acid reacts with iron filings.

 (āϘ) āĻĒাāϤāϞ āĻšাāχāĻĄ্ā§°āĻ•্āϞ'ā§°িāĻ• āĻāϚিāĻĄে āϞোā§° āĻĢাāχāϞিংā§° āϏৈāϤে āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āϕ⧰ে।

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6. Compounds such as alcohols and glucose also contain hydrogen but are not categorised as acids. Describe an Activity to prove it.

ā§Ŧ. āĻāϞāĻ•āĻšāϞ āφ⧰ু āĻ—্āϞুāĻ•োāϜ⧰ āĻĻā§°ে āϝৌāĻ—āĻŦোā§°āϤ āĻšাāχāĻĄ্ā§°āϜেāύ āĻĨাāĻ•ে āĻ•িāύ্āϤু āχāϝ়াāĻ• āĻāϚিāĻĄ āĻšিāϚাāĻĒে āĻļ্ā§°েāĻŖীāĻŦāĻĻ্āϧ āϕ⧰া āύāĻšāϝ়। āχāϝ়াāĻ• āĻĒ্ā§°āĻŽাāĻŖ āϕ⧰িāĻŦāϞৈ āĻ•াā§°্āϝāĻ•āϞাāĻĒ āĻāϟা āĻŦā§°্āĻŖāύা āϕ⧰āĻ•।

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7. Why does distilled water not conduct electricity, whereas rain water does?

ā§­. āĻĒাāϤāύ āϕ⧰া āĻĒাāύীāϝ়ে āĻ•িāϝ় āĻŦিāĻĻ্āϝুā§Ž āĻĒā§°িāĻŦāĻšāύ āύāϕ⧰ে, āφāύāĻšাāϤে āĻŦā§°āώুāĻŖā§° āĻĒাāύীāϝ়ে āϕ⧰ে?

  Ans-


 8. Why do acids not show acidic behavior in the absence of water?

 ā§Ž. āĻĒাāύীā§° āĻ…āĻ­াā§ąāϤ āĻāϚিāĻĄে āĻ•িāϝ় āĻāϚিāĻĄিāĻ• āφāϚ⧰āĻŖ āĻĒ্ā§°āĻĻā§°্āĻļāύ āύāϕ⧰ে?

  Ans-


9. Five solutions A,B,C,D and E when tested with universal indicator showed pH as 4,1,11,7 and 9, respectively. Which solution is

⧝. āχāωāύিāĻ­াā§°্āϚেāϞ āχāĻŖ্āĻĄিāĻ•েāϟ⧰⧰ āϏৈāϤে āĻĒā§°ীāĻ•্āώা āϕ⧰াā§° āϏāĻŽāϝ়āϤ āĻĒাঁāϚāϟা āϏāĻŽাāϧাāύ āĻ,āĻŦি,āϚি,āĻĄি āφ⧰ু āχ-āϤ āĻĒিāĻāχāϚ āĻ•্ā§°āĻŽাāύ্āĻŦāϝ়ে 4,1,11,7 āφ⧰ু 9 āĻšিāϚাāĻĒে āĻĻেāĻ–ুāĻ“ā§ąা āĻšৈāĻ›িāϞ। āĻ•োāύāϟো āϏāĻŽাāϧাāύ

 (a) neutral?                    (b) strongly alkaline?

(āĻ•) āύিā§°āĻĒেāĻ•্āώ?                  (āĻ–) āĻļāĻ•্āϤিāĻļাāϞীāĻ­াā§ąে āĻ•্āώাā§°ীāϝ়?

 (c) strongly acidic?                     (d) weakly acidic?

(āĻ—) āĻļāĻ•্āϤিāĻļাāϞীāĻ­াā§ąে āĻāϚিāĻĄিāĻ•?       (āϘ) āĻĻুā§°্āĻŦāϞāĻ­াā§ąে āĻāϚিāĻĄিāĻ•?

 (e) weakly alkaline?

(āĻ™) āĻĻুā§°্āĻŦāϞāĻ­াā§ąে āĻ•্āώাā§°ীāϝ়?

  Ans-


Arrange the pH in increasing order of hydrogen-ion concentration.

āĻšাāχāĻĄ্ā§°āϜেāύ-āφāϝ়āύ āϘāύāϤ্āĻŦ āĻŦৃāĻĻ্āϧি āϕ⧰াā§° āĻ•্ā§°āĻŽāϤ āĻĒি.āĻāχāϚ. āϏāϜাāĻ“āĻ•।

 10. Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCI) is added to test tube A, while acetic acid (CH,COOH) is added to test tube B. Amount and concentration taken for both the acids are same. In which test tube will the fizzing occur more vigorously and why?

 ā§§ā§Ļ. āĻĒā§°ীāĻ•্āώা āύāϞীāϤ āϏāĻŽাāύ āĻĻৈā§°্āϘ্āϝ⧰ āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ ā§°িāĻŦāύ āĻ—্ā§°āĻšāĻŖ āϕ⧰া āĻšāϝ় āĻ āφ⧰ু āĻŦি. āĻšাāχāĻĄ্ā§°āĻ•্āϞ'ā§°িāĻ• āĻāϚিāĻĄ (āĻāχāϚāϚিāφāχ) āĻĒā§°ীāĻ•্āώা āύāϞী āĻ-āϤ āϝোāĻ— āĻĻিāϝ়া āĻšāϝ়, āφāύāĻšাāϤে āĻĒā§°ীāĻ•্āώা āύāϞী āĻŦি-āϤ āĻāϚিāϟিāĻ• āĻāϚিāĻĄ (āϚিāĻāχāϚ,āϚি.āĻ“.āĻ“.āĻāχāϚ.) āϝোāĻ— āĻĻিāϝ়া āĻšāϝ়। āĻĻুāϝ়োāϟা āĻāϚিāĻĄā§° āĻŦাāĻŦে āϞোā§ąা āĻĒā§°িāĻŽাāĻŖ āφ⧰ু āϘāύāϤ্āĻŦ āĻāĻ•ে। āĻ•োāύāϟো āĻĒā§°ীāĻ•্āώা āύāϞীāϤ āĻĢিāϜিং āĻ…āϧিāĻ• āϜোā§°েā§°ে āϘāϟিāĻŦ āφ⧰ু āĻ•িāϝ়?

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11. Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.

ā§§ā§§. āϏāϤেāϜ āĻ—াāĻ–ীā§°āϤ 6 āĻĒিāĻāχāϚ āφāĻ›ে। āĻĻৈāϞৈ āĻĒā§°িā§ąā§°্āϤāύ āĻšোā§ąাā§° āϞāĻ—ে āϞāĻ—ে āĻĒিāĻāχāϚ āĻ•েāύেāĻĻā§°ে āϏāϞāύি āĻš'āĻŦ āĻŦুāϞি āφāĻĒুāύি āĻ­াāĻŦে? āφāĻĒোāύাā§° āωāϤ্āϤ⧰ āĻŦ্āϝাāĻ–্āϝা āϕ⧰āĻ•।

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12. A milkman adds a very small amount of baking soda to fresh m

⧧⧍. āĻāϜāύ āĻ—াāĻ–ীā§°ā§° āĻŽাāύুāĻšে āϏāϤেāϜ āĻ—াāĻ–ীā§°āϤ āĻ…āϤি āĻ•āĻŽ āĻĒā§°িāĻŽাāĻŖā§° āĻŦেāĻ•িং āϚāĻĄা āϝোāĻ— āĻĻিāϝ়ে।

 (a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?

 (āĻ•) āϤেāĻ“ঁ āϏāϤেāϜ āĻ—াāĻ–ীā§°ā§° āĻĒিāĻāχāϚ 6 ā§° āĻĒā§°া āϏাāĻŽাāύ্āϝ āĻ•্āώাā§°ীāϝ়āϞৈ āĻ•িāϝ় āϏ্āĻĨাāύাāύ্āϤ⧰ āϕ⧰ে?

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(b) Why does this milk take a long time to set as curd?

(āĻ–) āĻāχ āĻ—াāĻ–ীā§°āĻĻৈ āĻšিāϚাāĻĒে āύিā§°্āϧাā§°āĻŖ āϕ⧰িāĻŦāϞৈ āĻ•িāϝ় āĻĻীāϘāϞীāϝ়া āϏāĻŽāϝ় āϞাāĻ—ে?

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13. Plaster of Paris should be stored in a moisture-proof container. Explain why?

ā§§ā§Š. āĻĒ্āϞাāώ্āϟাā§° āĻ…āĻĢ āĻĒেā§°িāĻ› āĻāϟা āφ⧰্āĻĻ্ā§°āϤা-āĻĒ্ā§°āϤিā§°োāϧী āĻĒাāϤ্ā§°āϤ āϏংā§°āĻ•্āώāĻŖ āϕ⧰িāĻŦ āϞাāĻ—ে। āĻ•িāϝ় āĻŦā§°্āĻŖāύা āϕ⧰িāĻŦ?

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14. What is a neutralisation reaction? Give two examples.

ā§§ā§Ē. āύিāώ্āĻ•্ā§°িāϝ়āϕ⧰āĻŖā§° āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āĻ•ি? āĻĻুāϟা āωāĻĻাāĻšā§°āĻŖ āĻĻিāϝ়āĻ•।

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15. Give two important uses of washing soda and baking soda.

ā§§ā§Ģ. ā§ąাāĻ›িং āϚāĻĄা āφ⧰ু āĻŦেāĻ•িং āϚāĻĄাā§° āĻĻুāϟা āĻ—ুā§°ুāϤ্āĻŦāĻĒূā§°্āĻŖ āĻŦ্āĻ¯ā§ąāĻšাā§° āĻĻিāϝ়āĻ•।

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Question Type Jit Bora.