Give an example of a chemical reaction or chemical change for each of the following
situations:
(a) A change in colour is observed.
(b) A gas is evolved.
(c) Sound is produced.
(d) Heat is produced.
(e) Change in taste is observed.
(f) Light is produced.
Answers
Answer:
Reaction between copper sulphate soludon and zinc metal. The blue colour of the copper sulphate solution fades away and a red brown metallic copper is formed,
Reaction between baking soda and vinegar. Baking soda on reaction with vinegar produces carbon dioxide.
Burning of crackers.
Reaction of silver nitrate and potassium chloride. A precipitate of silver chloride is formed.
When water is heated above boiling point, it converts into vapours.
Water droplets appear on the outside of a bottle containing cold water.
Answer:
1. Reaction between copper sulphate soludon and zinc metal. The blue colour of the copper sulphate solution fades away and a red brown metallic copper is formed,
2.Reaction between baking soda and vinegar. Baking soda on reaction with vinegar produces carbon dioxide.
3.Burning of crackers.
4.Reaction of silver nitrate and potassium chloride. A precipitate of silver chloride is formed.
5.When water is heated above boiling point, it converts into vapours.
6.Water droplets appear on the outside of a bottle containing cold water.
Explanation: