Question

Write one chemical equation for the chemical reaction in which the following has taken place:

Change in colour

Mention colour change along with equation.

Answer 1

The reaction between iron and copper sulphate changes the blue colour of copper sulphate to a pale green.
$$\underset{\mathrm{Iron}}{\mathrm{Fe}{\phantom{A}}_{(\mathrm{s})}}+\underset{(\mathrm{blue})}{\underset{\mathrm{Copper}\mathrm{sulphate}}{\mathrm{CuSO}{\phantom{A}}_4{\phantom{A}}_{(\mathrm{aq})}}}⟶\underset{(\mathrm{pale}\mathrm{green})}{\underset{\mathrm{Ferrous}\mathrm{sulphate}}{\mathrm{FeSO}{\phantom{A}}_4{\phantom{A}}_{(\mathrm{aq})}}}+\underset{\mathrm{Copper}}{\mathrm{Cu}{\phantom{A}}_{(\mathrm{s})}}$$