Chapter - 2 

Acids, Bases And Salts 

āĻāϚিāĻĄ, āĻ•্āώাā§°āĻ• āφ⧰ু āĻ˛ā§ąāĻŖ

EXERCISES

āĻŦ্⧟া⧟াāĻŽ

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

ā§§) āĻāϟা āĻĻ্ā§°ā§ą ā§°āĻ™া āϞিāϟāĻŽাāĻ› āύীāϞা āĻšৈ āĻĒā§°ে, āχāϝ়াā§° pH āĻšোā§ąাā§° āϏāĻŽ্āĻ­াā§ąāύা āĻĨাāĻ•ে

(a) 1         (b) 4       (c) 5          (d) 10

(āĻ•) ā§§       (āĻ–) ā§Ē      (āĻ—) ā§Ģ         (āϘ) ā§§ā§Ļ

Answer:- 

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—ুāĻĄ়ি āĻ•āĻŖী-āĻ–োāϞাā§° āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ি āĻāϟা āĻ—েāĻ› āĻĻিāϝ়ে āϝিāϝ়ে āϚূāĻŖ-āĻĒাāύী āĻ—াāĻ–ীā§°ā§° āĻĻā§°ে āϕ⧰ি āϤোāϞে। āĻĻ্ā§°ā§ąāϟোāϤ āĻĨাāĻ•ে

(a) NaCl     (b) HCI     (c) LiCl     (d) KCI

Answer:- 

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 HCl solution (the same solution as before) required to neutralise it will be

ā§Š) NaOH ā§° ā§§ā§Ļ āĻŽিāϞিāϞিāϟাā§° āĻĻ্ā§°ā§ąāĻŖ HCl ā§° ā§Ž āĻŽিāϞিāϞিāϟাā§° āĻĻ্ā§°ā§ąāĻŖেā§°ে āϏāĻŽ্āĻĒূā§°্āĻŖā§°ূāĻĒে āύিāώ্āĻ•্ā§°িāϝ় āĻšোā§ąা āĻĻেāĻ–া āϝাāϝ়। āϝāĻĻি āφāĻŽি NaOH ā§° āĻāĻ•েāϟা āĻĻ্ā§°ā§ąā§° ⧍ā§Ļ āĻŽিāϞিāϞিāϟাā§° āϞāĻ“ঁ, āϤেāύ্āϤে āχāϝ়াāĻ• āύিāώ্āĻ•্ā§°িāϝ় āϕ⧰িāĻŦāϞৈ āĻĒ্ā§°āϝ়োāϜāύীāϝ় āĻĒā§°িāĻŽাāĻŖā§° HCl āĻĻ্ā§°ā§ą (āĻĒূā§°্āĻŦā§° āĻĻā§°ে āĻāĻ•েāϟা āĻĻ্ā§°ā§ąāĻŖ) āĻš’āĻŦ

(a) 4 mL                    (b) 8 mL                     (c) 12 mL                            (d) 16 mL

(āĻ•) ā§Ē āĻŽিāϞিāϞিāϟাā§°     (āĻ–) ā§Ž āĻŽিāϞিāϞিāϟাā§°        (āĻ—) ⧧⧍ āĻŽিāϞিāϞিāϟাā§°             (āϘ) ā§§ā§Ŧ āĻŽিāϞিāϞিāϟাā§°

Answer:-

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

ā§Ē/ āĻŦāĻĻāĻšāϜāĻŽ ā§°োāĻ— āύিā§°াāĻŽāϝ়ā§° āĻŦাāĻŦে āϤāϞ⧰ āĻ•োāύāĻŦিāϧ āĻ”āώāϧ āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰া āĻšāϝ়?

(a) Antibiotic             (b) Analgesic          (c) Antacid             (d) Antiseptic

(āĻ•) āĻāύ্āϟিāĻŦাāϝ়āϟিāĻ•      (āĻ–) āĻŦিāώāύাāĻļāĻ•         (āĻ—) āĻāύ্āϟাāϚিāĻĄ          (āϘ) āĻāύ্āϟিāϚেāĻĒ্āϟিāĻ•

Answer:-

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

5. - āϤেāϤিāϝ়া āϏংāϘāϟিāϤ āĻšোā§ąা āĻŦিāĻ•্ā§°িāϝ়াā§° āĻŦাāĻŦে āĻļāĻŦ্āĻĻ āϏāĻŽীāϕ⧰āĻŖ āφ⧰ু āϤাā§° āĻĒিāĻ›āϤ āϏুāώāĻŽ āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–া।

(a) dilute sulphuric acid reacts with zinc granules.

(āĻ•) āĻĒাāϤāϞ āĻ›াāϞāĻĢিāω⧰িāĻ• āĻāϚিāĻĄে āϜিংāϕ⧰ āĻĻাāύাāĻŦোā§°ā§° āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ে।

(b) dilute hydrochloric acid reacts with magnesium ribbon.

(āĻ–) āĻĒাāϤāϞ āĻšাāχāĻĄ্ā§°āĻ•্āϞ⧰িāĻ• āĻāϚিāĻĄে āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ āĻĢিāϤাā§° āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ে।

(c) dilute sulphuric acid reacts with aluminium powder.

(āĻ—) āĻĒাāϤāϞ āĻ›াāϞāĻĢিāω⧰িāĻ• āĻāϚিāĻĄে āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ—ুāĻĄ়িā§° āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ে।

(d) dilute hydrochloric acid reacts with iron filings.

(āϘ) āĻĒাāϤāϞ āĻšাāχāĻĄ্ā§°āĻ•্āϞ⧰িāĻ• āĻāϚিāĻĄে āϞোā§° āĻĢাāχāϞিāϙ⧰ āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ে।

Answer:-

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§°āϤো āĻšাāχāĻĄ্ā§°’āϜেāύ āĻĨাāĻ•ে āϝāĻĻিāĻ“ āĻāϚিāĻĄ āĻšিāϚাāĻĒে āĻļ্ā§°েāĻŖীāĻ­ুāĻ•্āϤ āύāĻšāϝ়। āĻāϟা āĻ•াā§°্āϝāĻ•āϞাāĻĒ āĻĒ্ā§°āĻŽাāĻŖ āϕ⧰িāĻŦāϞৈ āĻŦā§°্āĻŖāύা āϕ⧰া।

Answer:-

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

ā§­/ āĻĄিāώ্āϟিāϞāĻĄ āĻĒাāύীāϝ়ে āĻŦিāĻĻ্āϝুā§Ž āĻĒā§°িāĻŦাāĻšী āύāϕ⧰ে, āφāύāĻšাāϤে āĻŦā§°āώুāĻŖā§° āĻĒাāύীāϝ়ে āĻ•িāϝ় āϕ⧰ে?

Answer:-

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

ā§Ž) āĻĒাāύীā§° āĻ…āύুāĻĒāϏ্āĻĨিāϤিāϤ āĻāϚিāĻĄāĻŦোā§°ে āĻ•িāϝ় āĻāϚিāĻĄিāĻ• āφāϚ⧰āĻŖ āĻĻেāĻ–ুā§ąাāĻŦ āύোā§ąাā§°ে?

Answer:-

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 āχāύāĻĄিāĻ•েāϟ⧰⧰ āϏৈāϤে āĻĒā§°ীāĻ•্āώা āϕ⧰িāϞে āĻĒাঁāϚāϟা āĻĻ্ā§°ā§ą A,B,C,D āφ⧰ু E āϝ়ে pH āĻ•্ā§°āĻŽে ā§Ē,ā§§,ā§§ā§§,ā§­ āφ⧰ু ⧝ āĻĻেāĻ–ুā§ąাāχāĻ›িāϞ। āĻ•োāύāϟো āϏāĻŽাāϧাāύ

(a) neutral? 

(āĻ•) āύিā§°āĻĒেāĻ•্āώ?

(b) strongly alkaline?

(āĻ–) āĻĒ্ā§°āĻŦāϞāĻ­াā§ąে āĻ•্āώাā§°āĻ•ীāϝ়?

 (c) strongly acidic?

(āĻ—) āĻĒ্ā§°āĻŦāϞāĻ­াā§ąে āĻ…āĻŽ্āϞীāϝ়?

 (d) weakly acidic? 

(āϘ) āĻĻুā§°্āĻŦāϞāĻ­াā§ąে āĻ…āĻŽ্āϞীāϝ়?

(e) weakly alkaline?

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

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

āĻšাāχāĻĄ্ā§°āϜেāύ-āφāϝ়āύ⧰ āϘāύāϤ্āĻŦā§° āĻŦৃāĻĻ্āϧি āĻĒোā§ąা āĻ•্ā§°āĻŽāϤ pH āϏāϜাāĻ“āĻ•।

Answer:-

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 (CH3COOH) 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 āύāϞী A āφ⧰ু B āϤ āϏāĻŽাāύ āĻĻৈā§°্āϘ্āϝ⧰ āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ āĻĢিāϤা āϞোā§ąা āĻšāϝ়।āĻĒā§°ীāĻ•্āώা āύāϞী A āϤ āĻšাāχāĻĄ্ā§°āĻ•্āϞ⧰িāĻ• āĻāϚিāĻĄ (HCI) āϝোāĻ— āϕ⧰া āĻšāϝ়, āφāύāĻšাāϤে āĻĒā§°ীāĻ•্āώা āύāϞী B āϤ āĻāϚিāϟিāĻ• āĻāϚিāĻĄ (CH3COOH) āϝোāĻ— āϕ⧰া āĻšāϝ়।āĻĻুāϝ়োāϟা āĻāϚিāĻĄā§° āĻŦাāĻŦে āϞোā§ąা āĻĒā§°িāĻŽাāĻŖ āφ⧰ু āϘāύāϤ্āĻŦ āϕ⧰া āĻšāϝ় āĻāĻ•েāχ. āĻ•োāύāϟো āϟেāώ্āϟ āϟিāωāĻŦāϤ āĻĢিāϜিং āĻ…āϧিāĻ• āϜোā§°েā§°ে āĻš’āĻŦ āφ⧰ু āĻ•িāϝ়?

Answer:-

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§°ā§° pH ā§Ŧ āĻšāϝ়, āĻĻৈāϞৈ āĻĒā§°িāĻŖāϤ āĻšোā§ąাā§° āϞāĻ—ে āϞāĻ—ে pH āĻ•েāύেāĻ•ৈ āϏāϞāύি āĻš’āĻŦ āĻŦুāϞি āφāĻĒুāύি āĻ­াāĻŦে? āφāĻĒোāύাā§° āωāϤ্āϤ⧰āϟো āĻŦুāϜাāχ āĻĻিāϝ়āĻ•।

Answer:-

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

⧧⧍) āϏāϤেāϜ āĻ—াāĻ–ীā§°āϤ āĻāϜāύ āĻ—াāĻ–ীā§° āĻĻিāϝ়া āĻŽাāύুāĻšে āĻ…āϤি āĻ•āĻŽ āĻĒā§°িāĻŽাāĻŖā§° āĻŦেāĻ•িং āĻ›’āĻĄা āĻŽিāĻšāϞাāχ āĻĻিāϝ়ে।

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

(āĻ•) āϤেāĻ“ঁ āϏāϤেāϜ āĻ—াāĻ–ীā§°ā§° pH ā§Ŧā§° āĻĒā§°া āĻ…āϞāĻĒ āĻ•্āώাā§°āĻ•ীāϝ়āϞৈ āĻ•িāϝ় āϏ্āĻĨাāύাāύ্āϤ⧰িāϤ āϕ⧰ে?

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

(āĻ–) āĻāχ āĻ—াāĻ–ীā§°āĻ• āĻĻৈ āĻšিāϚাāĻĒে āϏ্āĻĨাāĻĒāύ āϕ⧰িāĻŦāϞৈ āĻ•িāϝ় āĻŦāĻšু āϏāĻŽāϝ় āϞাāĻ—ে?

Answer:-

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

ā§§ā§Š) āĻĒেā§°িāϛ⧰ āĻĒ্āϞাāώ্āϟাā§° āφ⧰্āĻĻ্ā§°āϤা āύāĻĨāĻ•া āĻĒাāϤ্ā§°āϤ ā§°াāĻ–িāĻŦ āϞাāĻ—ে। āĻ•িāϝ় āĻŦুāϜাāχ āĻĻিāϝ়āĻ•?

Answer:-

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

ā§§ā§Ē) āύিāώ্āĻ•্ā§°িāϝ়āϕ⧰āĻŖ āĻŦিāĻ•্ā§°িāϝ়া āĻ•ি? āĻĻুāϟা āωāĻĻাāĻšā§°āĻŖ āĻĻিāϝ়া।

Answer:-

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

ā§§ā§Ģ) ā§ąাāĻļ্āĻŦিং āϚ’āĻĄা āφ⧰ু āĻŦেāĻ•িং āĻ›’āĻĄাā§° āĻĻুāϟা āĻ—ুā§°ুāϤ্āĻŦāĻĒূā§°্āĻŖ āĻŦ্āĻ¯ā§ąāĻšাā§° āĻĻিāϝ়āĻ•।

Answer:-


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Post ID: DABP001679