Question

A bivalent metal has $12$ equivalent weight. The molecular weight of its oxide is:

• A. 16
• B. 32
• C. 40
• D. 52

Answer 1

The correct option is C 40

Molecular weight= equivalent weight x n-factor

n- factor of the metal ion is 2.

So molecular weight is $(12$x$2)=24$

Since it is bivalent ion it requires only one oxygen atom combine to form an oxide.

Example, $MgO$ where $Mg$ is bivalent.

therefore, the molecular weight of the oxide is given as:

Molecular weight= molecular wt. of metal+ molecular wt. of oxygen

Molecular weight =$24+16=40$