Question

Which one of the following is not a neutral oxide?
A.$\;CO$
B.${H_2}O$
C.${N_2}O$
D. $N{a_2}O$

Answer 1

Oxides are compounds which are formed by reacting with oxygen (as its name suggests) and one or more oxygen atoms get attached to it. For example – ${H_2}O,{\text{ }}CO$.

Complete step by step answer:
Now when they get combined to oxygen, they form a compound which has specific characteristics like they are acidic, basic, or neutral and upon reaction with acid or base they form salts. Hence oxides have several types which are- Acidic, Basic, Amphoteric, Neutral oxides.
Acidic: - Which combines with water to give acid as final product are acidic oxides and form salt upon reacting with bases. E.g.- $S{O_2},{\text{ }}C{O_2}$
Basic: - Which combines with water to give bases as the final product are basic oxides and forms salt upon reacting with acids. E.g.- $CaO,{\text{ }}N{a_2}O$
Amphoteric: - which exhibits acidic as well as basic properties. E.g.- ZnO
Neutral: - Oxides which show neither acidic nor basic properties and do not form any salt when reacted with acid or base. E.g.- $CO,{\text{ }}NO,{\text{ }}{N_2}O$
Option a: - $CO$ is a neutral oxide because $CO$generally does not react with water to form any acidic or basic compound.
Option b: - ${H_2}O$ is also a neutral oxide which exists naturally and has a pH of 7 which is neutral.
Option c: - ${N_2}O$ is also a neutral oxide which does not react generally with acid or base to give salt.
Option d: - $N{a_2}O$is a basic oxide because $Na$ is in the first Group of periodic table which is alkali metals and upon reaction with ${H_2}O$ it forms a base.
Reaction: - $N{a_2}O{\text{ }} + {\text{ }}{H_2}O{\text{ }} \to {\text{ }}2NaOH$
$NaOH$is a base so it means $N{a_2}O$ is a basic oxide because it formed a base upon reaction with water.

So, the correct answer is D i.e. $\begin{gathered} N{a_2}O \\\ \\\ \end{gathered}$ which is not a neutral oxide.

Note:
To know the type of oxide generally, look at the position of the element in the periodic table. Generally, s-block elements are basic oxides (until there is an exception) p-block oxide are acidic as well as amphoteric oxides.