Table of Contents
Everyday items can be sorted into three groups: acids, bases, and neutral things. Take lemon juice, for instance; it’s acidic. Baking soda solution is basic, and common salt is neutral. Lemon juice is sour because it has citric acid. Baking soda has sodium bicarbonate, which makes it a base. Salt, like table salt, is made when an acid and a base react and cancel each other out.
Download Class 7 Chemistry Worksheet on Chapter 5 Acids, Bases and Salts Set 1 PDF
CBSE Class 7 Chemistry Chapter 5 Acids, Bases and Salts Worksheet – Set 1
Answer the following questions by choosing the correct option or filling in the blanks.
1. What is an acid?
a) A substance that tastes sour
b) A substance that tastes sweet
c) A substance that feels slippery
d) A substance that is odorless
Answer: a) A substance that tastes sour
2. Which of the following is a natural acid?
a) Lemon juice
b) Sugar
c) Milk
d) Water
Answer: a) Lemon juice
3. What is a base?
a) A substance that tastes sour
b) A substance that tastes bitter
c) A substance that feels slippery
d) A substance that is colorless
Answer: b) A substance that tastes bitter
4. Which of the following is a natural base?
a) Vinegar
b) Baking soda
c) Orange juice
d) Tea
Answer: b) Baking soda
5. What happens when an acid reacts with a base?
a) It produces water and salt
b) It produces water and sugar
c) It produces water and vinegar
d) It produces water and lemon juice
Answer: a) It produces water and salt
6. What is the pH scale used for?
a) To measure the temperature of a substance
b) To measure the acidity or basicity of a substance
c) To measure the weight of a substance
d) To measure the volume of a substance
Answer: b) To measure the acidity or basicity of a substance
7. Which of the following has a pH value less than 7?
a) Lemon juice
b) Water
c) Milk
d) Soap
Answer: a) Lemon juice
8. Which of the following has a pH value more than 7?
a) Vinegar
b) Orange juice
c) Baking soda solution
d) Coffee
Answer: c) Baking soda solution
9. What is a salt?
a) A substance formed by the reaction between an acid and a base
b) A sweet-tasting substance
c) A sour-tasting substance
d) A bitter-tasting substance
Answer: a) A substance formed by the reaction between an acid and a base
10. Which of the following is an example of a salt?
a) Sugar
b) Table salt
c) Lemon juice
d) Honey
Answer: b) Table salt
11. Complete the following chemical reaction:
Acid + Base → _______ + _______
Answer: Water + Salt
12. True or False: Acids are sour in taste and turn blue litmus paper red.
Answer: True
13. True or False: Bases are bitter in taste and turn red litmus paper blue.
Answer: True
14. Name one natural source of an acid and one natural source of a base.
Answer: Lemon juice (acid), Baking soda (base)
15. Explain the difference between an acid and a base in one sentence.
Answer: Acids taste sour and turn blue litmus paper red, while bases taste bitter and turn red litmus paper blue.
Bonus Question: What is the pH value of a neutral substance?
Answer: 7
Score: ____/15
