Science Revision Worksheet Acids Bases and salts

REVISION WORKSHEET

CLASS VII

SCIENCE – ACIDS BASES AND SALTS

1. While playing in a park, a child was stung by a wasp. Some people suggested applying the paste 

of baking soda while others suggested of lemon juice as remedy. Which remedy do you think is 

appropriate and why?

2. Match the following: 

a. Tartaric acid 1. Soap

b. Calcium hydroxide 2. Curd

c. Formic acid 3. Unripe mangoes

d. Lactic acid 4. Ant sting

e. Sodium hydroxide 5. Lime water

3. Ram was suffering from acidity. Is it advisable to give him orange juice in this situation and why?

4. Three liquids are given to you. One is hydrochloric acid; another is sodium hydroxide and third is 

a sugar solution. How will you identify them? You have only turmeric indicator.

5. What are indicators? Why do we use it? Give examples.

6. You are provided with three test tubes A, B and C.

Test tube A contains solution of tartaric acid

Test tube B contains soap solution

Test tube C contains pure water

What will you observe when you put

a. A piece of red litmus paper in each test tube

b. A piece of blue litmus paper in each test tube

c. A drops of phenolphthalein in each test tube

7. Classify the following substances into acidic and basic substances

Tomato juice, soap solution, toothpaste, lemon juice, vinegar

8. State differences between acids and bases

9. What is neutralisation reaction? Give one example.

10. Fill in the blanks:

a. Bases are _____in taste.

b. The chemical name of common salt is ______.

c. When you use blue litmus paper as an indicator, it gives the colour______ with acids.

d. Methyl orange has _______ colour in acidic solution.

11. The wastes of many factories contain acids. Why is it considered necessary to neutralize them 

before allowing the wasted to flow into water bodies?

12. When soil becomes too basic, plants do not grow well in it. To improve its quality, what must be 

added to the soil

a. Organic matter

b. Quick limec. Slaked lime

d. Calamine solution

13. Phenolphthalein is a synthetic indicator. Its colour in the acidic and basic solutions, respectively 

are

a. Red and blue

b. Blue and red

c. Pink and colourless

d. Colourless and pink

14. Turmeric is a natural indicator. On adding its paste to acid and base separately, which colours 

would be observed

a. Yellow in both acid and base

b. Yellow in acid and red in base

c. Pink in acid and yellow in base

d. Red in acid and blue in base

15. ‘LITMUS’ a natural dye is an extract of which of the following

a. China rose

b. Beet root

c. Lichen

d. Blue berry