What is the best description of the change that occurs when $Na_2O(s)$ is dissolved in water?

Question

$\begin{array}{1 1} \text{(a) Oxidation number of oxygen increases} \\ \text{ (b) Oxidation number of sodium decreases} \\ \text{ (c) Oxide ion accepts sharing in a pair of electrons} \\ \text{ (d) Oxide ion donates a pair of electrons} \end{array} $

Answer 1

Solution :

In water Na2O" role="presentation" style="position: relative;">Na2ONa2ONa_2O dissociates as -

Na2O+H2O→2Na++O2−" role="presentation" style="position: relative;">Na2O+H2O→2Na++O2−Na2O+H2O→2Na++O2−Na_2O +H_2O \to 2Na+ +O^{2-}

The oxide ion formed can form hydrogen bonds with water and is stabilised.

Thus it is easy for Na2O and all other oxides to dissolve in water as it brings about further stability in the system.