Question

9. Give an example of a chemical reaction for each of the following situations: [NCERT Exemplar]
(a) A change in colour is observed.
(b) A gas is evolved.
(c) Sound is produced.
(d) Formation of precipitate.
(e) Change of state from liquid to gas.
(f) Change of state from gas to liquid.​

Answer 1

Explanation:

a. Displacement reaction of Iron and Copper Sulphate solution

b. Reaction between Hydrochloric acid and Zinc granules

c. Reaction between Hydrochloric acid and Zinc granules when h2 is passed from soap solution, bubbles are formed along with pop up sound.

d. Reaction of double displacement between Barium Sulphate and Sodium chloride, sodium sulphate is the precipitate is formed.

e. Reaction between Hydrochloric acid and Zinc granules, hydrogen present in Hydrochloric acid is converted from liquid to gas as hydrogen is liberated.

f. Reaction of hydrogen gas and oxygen gas, water is formed as a result of liquid