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

Hint: 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.