NIOS Class 10 Science and Technology Chapter 8: ACIDS, BASES AND SALTS– Chapter-wise Important Questions and Answers

NIOS Class 10 Science and Technology Chapter 8: ACIDS, BASES AND SALTS | MCQs, Short & Long Answer Questions | 8. ACIDS, BASES AND SALTS

Chapter 8: ACIDS, BASES AND SALTS

INTEXT QUESTION 8.1

1. Put the following substances in acid or base bottle.

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(a) Milk of magnesia

(b) gastric juice in humans

(c) soft drinks

(d) lime water

(e) vinegar

(f) soap

Answer: The classification is :

Substance	Acid / Base
(a) Milk of magnesia	Base
(b) Gastric juice in humans	Acid
(c) Soft drinks	Acid
(d) Lime water	Base
(e) Vinegar	Acid
(f) Soap	Base

 

2. What will happen if you add a drop of the following on a cut unripe apple, curd, causting soda solution and soap solution.

(i) phenolphthalein

(ii) litmus

Answer: The effect of indicators on the given substances is:

Substance	Phenolphthalein	Litmus
Cut unripe apple (acidic)	Remains colourless	Turns blue litmus red
Curd (acidic)	Remains colourless	Turns blue litmus red
Caustic soda solution (basic)	Turns pink	Turns red litmus blue
Soap solution (basic)	Turns pink	Turns red litmus blue

 

INTEXT QUESTIONS 8.2

1. Name the substances in which the following acids are present:

(a) Ethanoic acid (b) Tartaric acid

Answer: (a) Ethanoic acid is present in vinegar, which gives it a sour taste.
(b) Tartaric acid is present in tamarind and grapes.

 

2. Which of these acids would be partially dissociated in their aqueous solution?

(a) HBr (b) HCN     (c) HNO3 (d) C2H5COOH

Answer: The acids that would be partially dissociated in aqueous solution are HCN and C₂H₅COOH because they are weak acids.

[ HBr → Strong acid → Completely dissociates .

  HCN → Weak acid → Partially dissociates .

  HNO₃ → Strong acid → Completely dissociates.

 C₂H₅COOH (Propanoic acid) → Weak acid → Partially dissociates . ]

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