What happens when sodium metal is dropped in water?

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?

(i) ${ H }_{ 2 }$ gas is evolved which catches fire due to the liberation of extreme heat in the reaction.

2 Na (s) + 2 $H { 2 }O$(l) -------> 2NaOH (aq) + ${ H }{ 2 }$(g)

(ii) $Na _{ 2 }$$O _{ 2 }$ along with a small amount of $Na _{ 2 }O$ is formed.

4 Na (s) + 02 (g) ------ > 2 $Na _{ 2 }O$ (s)

$Na _{ 2 }O$ (s) +1/2 $O _{ 2 }$ ------- > $Na _{ 2 }$$O _{ 2 }$ (s)

(iii) $H _{ 2 }$$O _{ 2 }$ is formed when sodium peroxide is dissolved in water.

$Na _{ 2 }$$O _{ 2 }$ (s) + 2 $H _{ 2 }O$ (l) ------- > 2 NaOH (aq) + $H _{ 2 }$$O _{ 2 }$(l)