Question

Question 16

Which one of the following processes involves chemical reactions?

(a) Storing of oxygen gas under pressure in a gas cylinder.
(b) Liquefaction of air.
(c) Keeping petrol in a china dish in the open.
(d) Heating copper wire in presence of air at high temperature.

Answer 1

Option (d) is correct.

A chemical reaction is a change in which one or more substance or reactant(s) react to give new substance(s) with entirely different properties.

When copper wire is heated, it reacts with the oxygen of the air to form copper(II) oxide. The reaction occurs as follows:

$2\text{Cu (s)}+{\text{O}}_2\text{(g)}\to 2\text{CuO(s)}$