$2 \, g$ of ferrous sulphate crystals are heated in a boiling tube.
$(i)$ State the colour of ferrous sulphate crystals both before heating and after heating.
$(ii)$ Name the gases produced during heating.
$(iii)$ Write the chemical equation for the reaction.

(N/A) $(i)$ Before heating: Pale green. After heating: Brown or reddish-brown.
$(ii)$ The gases produced are sulphur dioxide $(SO_{2})$ and sulphur trioxide $(SO_{3})$.
$(iii)$ The chemical equation for the thermal decomposition of ferrous sulphate is:
$2FeSO_{4}(s) \xrightarrow{\text{Heat}} Fe_{2}O_{3}(s) + SO_{2}(g) + SO_{3}(g)$