A bivalent metal has equivalent mass 12. Molecular mass of its oxide will be:

Correct option is D

The correct answer is (d) 40.

• Equivalent mass

• $$=Atomic mass= \frac{\text{Atomic mass}}{\text{Valency}}$$​

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• Atomic mass of metal $=\text{Equivalent mass}\times \text{Valency}=12\times 2=24$

• The metal oxide formula for a bivalent metal is $\text{MO}$, meaning one atom of metal combines with one atom of oxygen.

• Atomic mass of oxygen = 16

• Molecular mass of oxide $=\text{Atomic mass of metal}+\text{Atomic mass of oxygen}=24+16=40$