• # question_answer 1) What happens when: (i) sodium is dropped in water? (ii) sodium metal is heated in free supply of air? (iii) sodium peroxide is dissolved in water?

(i) ${{H}_{2}}$gas is evolved which catches fire as huge amount of heat energy is released. $2Na+2{{H}_{2}}O\to 2NaOH+{{H}_{2}}$ (ii) Sodium peroxide is formed. It always contains small amounts of$N{{a}_{2}}O$. $4Na+{{O}_{2}}\to 2N{{a}_{2}}O$ $2N{{a}_{2}}O+{{O}_{2}}\to 2N{{a}_{2}}{{O}_{2}}$ (iii) ${{H}_{2}}{{O}_{2}}$is formed. $N{{a}_{2}}{{O}_{2}}+2{{H}_{2}}O\to 2NaOH+{{H}_{2}}{{O}_{2}}$ The reaction is exothermic. ${{H}_{2}}{{O}_{2}}$gets decomposed. $2{{H}_{2}}{{O}_{2}}\to 2{{H}_{2}}O+{{O}_{2}}.$