Question

In the following reactions, ZnO is respectively acting as a/an :
i.) $ZnO + N{a_2}O \to N{a_2}Zn{O_2}$
ii.) $ZnO + C{O_2} \to ZnC{O_3}$
a.) acid and acid
b.) acid and base
c.) base and acid
d.) base and base

Answer 1

Hint: An acid is a compound that has the ability to accept electrons and base is the compound that can donate electrons. The amphoteric compound is the one that has dual character. Some amphoteric oxides can act as acid as well as base. The ZnO is an amphoteric oxide. It is less acidic than carbon dioxide while more than sodium oxide.

Complete Solution :
First, let us understand the term amphoteric oxide.
The oxide is a compound of an element having oxygen attached. The amphoteric means that have dual character. The amphoteric oxides are the one that have both the properties of acids as well as bases. Such a compound will acta s acid in the presence of a base and as base in the presence of an acid.
Further, we know that the acid is the compound that can accept electrons and base is a compound that can donate electrons.

So, now let us see the reactions written.
The first reaction is -
i.) $ZnO + N{a_2}O \to N{a_2}Zn{O_2}$

In this reaction, the ZnO is an acid and the $N{a_2}O$ is the base.
ii.) $ZnO + C{O_2} \to ZnC{O_3}$

In this reaction, the ZnO acts as the base and the carbon dioxide as the acid.
So, the ZnO is acidic in the first reaction and base in the second reaction.
So, the correct answer is “Option B”.

Note: It must be noted that metallic oxides are mostly basic and non-metallic oxides are acidic. Some of the metallic oxides can behave as amphoteric oxides. The Zinc Oxide is a white powder which is insoluble in water. It has a high refractive index and high thermal conductivity.