What happens when : $(i)$ sodium metal is dropped in water? $(ii)$ sodium metal is heated in free supply of air? $(iii)$ sodium peroxide dissolves in water?

(N/A) $(i)$ When $Na$ metal is dropped in water,it reacts violently to form sodium hydroxide and hydrogen gas. The chemical equation involved in the reaction is: $2Na_{(s)} + 2H_{2}O_{(l)} \rightarrow 2NaOH_{(aq)} + H_{2(g)}$
$(ii)$ On being heated in air,sodium reacts vigorously with oxygen to form sodium peroxide. The chemical equation involved in the reaction is: $2Na_{(s)} + O_{2(g)} \rightarrow Na_{2}O_{2(s)}$
$(iii)$ When sodium peroxide is dissolved in water,it is readily hydrolysed to form sodium hydroxide and hydrogen peroxide. The chemical equation involved in the reaction is: $Na_{2}O_{2(s)} + 2H_{2}O_{(l)} \rightarrow 2NaOH_{(aq)} + H_{2}O_{2(aq)}$