Question

Among the following which one is the most basic?

• A. $\mathrm{ZnO}$
• B. $\mathrm{MgO}$
• C. ${\mathrm{Al}}_2{\mathrm{O}}_3$
• D. ${\mathrm{N}}_2{\mathrm{O}}_5$

Answer 1

The correct option is B

$\mathrm{MgO}$

Explanation for correct option:

B. $\mathrm{MgO}$

Metal oxide:

• A metal oxide is a crystalline solid that is composed of a metal cation and an oxide anion.
• Metallic oxide is alkaline in nature.
• Almost all metals combine with oxygen to form metal oxides.
• General reaction for the formation of metal oxide:

$\mathrm{Metal}+\mathrm{Oxygen}\to \mathrm{Metal}\mathrm{oxide}$

Example of a metallic oxide:

• Magnesium oxide$\left(\mathrm{MgO}\right)$is a metallic oxide.
• The chemical reaction for the formation of a metallic oxide is depicted below:

$2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

The acidic character of oxide of elements decreases down a group and increases across a period, from left to right.

Explanation for correct options:

A. $\mathrm{ZnO}$ is an amphoteric oxide.

C. ${\mathrm{Al}}_2{\mathrm{O}}_3$ is an amphoteric oxide.

D. ${\mathrm{N}}_2{\mathrm{O}}_5$ is an oxide of non-metallic, thus it is an acidic oxide.

Hence, the correct option is B i.e. $\mathrm{MgO}$.