What is the best description of the change that occurs when $N{a}_{2}O\left(s\right)$ is dissolved in water?

Q. (a) What is the nature of the oxide SO₂? What happens when it is dissolved in water? Write the chemical equation of the reaction involved.
(b) What is the nature of the oxide Na₂O? What happens when it is dissolved in water? Write the chemical equation of the reaction involved.

Q. When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and B cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.

(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A.Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.

Q. What is the nature of $N{a}_{2}O$ ? What happens when it is dissolve in water ? Write equation.

Q. What is the nature of $N{a}_{2}O$ ? What happens when it is dissolve in water ? Write equation. [3 marks]