Question

“Sodium cannot be kept open in atmospheric air, and cannot be stored in water. So it is stored in kerosene.” Give explanation for the above statement with its chemical equation.

Answer 1

Sodium which is placed above in the reactivity series reacts vigorously with water and oxygen. 

4Na (s) + O₂ (g) → 2Na₂O (s) 

2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g)

This NaOH reacts with CO₂ in the atmospheric air and forms sodium carbonate. 

2NaOH (s) + CO₂ (g) → Na₂CO₃ + H₃O (l) To avoid the reaction with O₂ , H₂O and CO₂ , sodium is stored in kerosene.

Answer 2

Sodium reacts vigorously with water and oxygen.

Chemical Equations:

4Na_(s) + O₂​_(g) ⟶ 2Na₂​O_(s)

2Na_(s) + 2H₂​O_(l) ⟶ 2NaOH_(aq) + H_2(g)

This NaOH reacts with CO₂​ present in the atmosphere to form sodium carbonate.

Chemical Equations:

2NaOH_(s) + CO_2(g) ⟶ Na₂CO_3(s)​ + H₂​O_(l)

To avoid the reaction with O₂​, H₂​O and CO₂​, which is highly exothermic (can also produce flames), sodium is stored in kerosene.