Question

Equivalent weight of a metal is $12$. Equivalent weight of $Y$ in the compound $M{Y}_2$ is:

[Molecular weight of $M{Y}_2$ is $36$]

• A. 24
• B. 6
• C. 12
• D. 16

Answer 1

The correct option is B 6

Let the valency of metal M be $+x$ and that of Y be $-0.5x$ .
Molecular mass of the compound will be $12x+y\times 0.5x$, where $y$ is the equivalent mass of element Y.
$36=12x+y\times 0.5x$
Only 1 case with an integer valency $x$ satisfies this equation, viz. $x=2andy=6$.