Page 50 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

7. ........................... is the most common type of salt.

Ans. Sodium chloride (NaCl)
8. ......................... is formed by the reaction of a strong acid with a weak base.

Ans. Acidic salt
C. State whether the following statements are true (T) or false (F).

1. Nitric acid is a strong acid.

2. Acid + base  salt + hydrogen (gas)
3. Our stomach contains nitric acid.

4. When an ant bites, it injects acetic acid into us.
5. The wastes of factories are non-toxic.

6. Many food items contain organic acids.
7. When metals burn in oxygen, respective metallic oxides are formed which are acidic

in nature.

8. Salt is a bad conductor of electricity.
Ans. 1. (T) 2. (F) 3. (F) 4. (F) 5. (F) 6. (T) 7. (F) 8. (T)

D. Match the following.
Column A Column B

1. Tartaric acid (a) Soap
2. Calcium hydroxide (b) Curd

3. Formic acid (c) Unripe mangoes

4. Sodium hydroxide (d) Ant’s sting
5. Lactic acid (e) Lime water

Ans. 1. (c) 2. (e) 3. (d) 4. (a) 5. (b)
E. Very short-answer questions

1. Harman was suffering from acidity. Is it advisable to give orange juice to bring relief?
Why?

Ans. No, it is not advisable to give orange juice to Harman because orange juice is acidic in

nature. It can increase the acidity in the stomach, which might worsen the symptoms.
2. Differentiate between an acid and a base on the parameters of touch and taste.
Ans. Touch:

• Acids  sting or burn.

• Bases  slippery or soapy.
Taste :

• Acids  sour.
• Bases  bitter.

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