Question

18- Which one of the given processes involves chemical reactions? A) Storing of oxygen gas under pressure in a gas cylinder B) Keeping petrol in a China dish in the open C) Liquefaction of air D) Heating copper wire in the presence of air at high temperature​

Answer 1

Answer:

D) Heating copper wire in the presence of air at high temperature is a chemical reaction

Answer 2

Explanation:

This formation of a thin layer of copper oxide is certainly a chemical reaction. In the first three options given here, there is no involvement of chemical reaction. Hence, Heating copper wire in the presence of air at high temperature is a process that involves chemical reaction.