Question

Sodium oxide $N{a_2}O$ is added to excess cold water. Which of the following would occur?
A.No appreciable reaction
B.Reaction to yield hydrogen and an aqueous solution of sodium hydroxide.
C.Reaction to yield an aqueous solution of sodium hydroxide
D.Reaction to yield oxygen and an aqueous solution of sodium hydroxide.

Answer 1

Hint: $N{a_2}O$ is a chemical compound which is a strong basic oxide due to the presence of oxide ions. It is anhydride form of sodium hydroxide. It reacts with cold water to give sodium hydroxide which is an exothermic reaction. Both sodium and oxygen separately are reactive elements.

Complete answer:
- Sodium is a chemical element with symbol $Na$ and atomic number 11. It is an alkali metal which forms metal hydroxide which is alkaline in nature. It is a highly reactive element which is stored under oil so that it does not react with air and water. It readily reacts with water. It is a very soft metal that can be cut with even a butter knife. It is an essential element for our body to maintain water balance and proper muscle functioning.
- Oxygen is found in the atmosphere. It is highly reactive non-metal and has a chemical symbol of $O$ and an atomic number of 8. It forms oxides with elements and behaves as an oxidizing agent. Oxygen is used for respiration and is mainly used to manufacture steel. It takes two oxygen atoms to form one oxygen molecule and therefore, it is written as ${O_2}$. Sodium oxide is a chemical compound with the formula $N{a_2}O$. $N{a_2}O$ is a strong basic oxide as it contains oxide ions which combine with hydrogen ions and form a strong basic oxide. When sodium burns in air it burns with a bright yellow light.
- Sodium oxide reacts with water to form sodium hydroxide. It is an exothermic reaction.
$N{a_2}O + {H_2}O \to 2NaOH$
Thus, according to the question we know that $N{a_2}O$ reacts with cold water to form aqueous solution of sodium hydroxide.

So, the correct answer is (C).

Note:
Sodium oxide is an ionic compound as it contains both a metal and a non metal. Hence it has the opposite composition of interactions between its molecules. It is a very toxic compound as it causes damage to skin, eyes and respiratory system. Sodium oxide has a high melting point and is brittle.