CBSE Class 7 Science Chapter 2 Exploring Substances: Acidic, Basic and Neutral Worksheet - Free Download

Q.1. True/False

(i) Nitric acid turns red litmus blue.

(ii) Sodium hydroxide turns blue litmus red.

(iii) Sodium hydroxide and hydrochloric acid neutralize each other and form salt and water.

(iv) An indicator is a substance that shows different colors in acidic and basic solutions.

(v) Tooth decay is caused by the presence of a base.

(vi) If an indicator changes color with a base, it does not change color with an acid.

Q.2. Fill in the blanks.

(i) Change of color in an acid and a base depends on the type of the ____.

(ii) Acid turns ____ litmus red.

(iii) Bases turn ___ litmus blue.

(iv) Litmus has a ____ color in distilled water.

(v) In the neutralization reaction a new substance is formed. This is called ____.

(vi)  Lemon juice is ____ in nature.

Answer the following Questions 

Q.3. Why do curd, lemon juice, orange juice, and vinegar taste sour?

Q.4. Tom rubs a solution between his fingers and feels soapy, what is the nature of that solution?

Q.5. What do you mean by neutral solution? Give examples.

Q.6. State a few properties of acids.

Q.7. Which acid is present in an ant sting?

Q.8. What is the nature of distilled water?

Q.9. Which is the most commonly used natural indicator?

Q.10. Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.

Q.11. Why factory waste is neutralised before disposing it of in the water bodies?

Q.12. Give some examples of acids and bases that we encounter in day-to-day life.

Q.13. What is the effect of the China rose indicator on acidic and basic solutions?

Q.14. Why a turmeric stain on my white shirt is turned to red when it is washed with soap.

Q.15. Is the distilled water acidic/basic/neutral? How would you verify it?