$A$ metal $E$ is stored under kerosene oil. When a small piece of it is left open in the air,it catches fire. When the product formed is dissolved in water,it turns red litmus blue.
$(i)$ Name the metal $E$.
$(ii)$ Write the chemical equations for the reaction when it is exposed to air and when the product is dissolved in water.
$(iii)$ Explain the process by which the metal is obtained from its molten chloride.

(A) $(i)$ The metal $E$ is Sodium $(Na)$.
$(ii)$ Reaction with air: $4Na + O_{2} \rightarrow 2Na_{2}O$.
Reaction with water: $Na_{2}O + H_{2}O \rightarrow 2NaOH$.
$(iii)$ Sodium is obtained from molten sodium chloride $(NaCl)$ by the process of electrolytic reduction (electrolysis). In this process,an electric current is passed through the molten salt.
At cathode: $Na^{+} + e^{-} \rightarrow Na$ (Reduction).
At anode: $2Cl^{-} \rightarrow Cl_{2} + 2e^{-}$ (Oxidation).