Question

The equivalent weight of a divalent metal whose chloride has vapour density equal to $60$, is:

• A. $30$
• B. $49$
• C. $24.5$
• D. $16.5$

Answer 1

The correct option is B $49$

Vapour density $=\frac{Molecularwt.ofcompound}{2}$

Molecular wt. of chloride $\left({MCl}_2\right)=2\times 60=120$

[Metal is divalent, so two atoms of chlorine]

Molecular wt. of ${MCl}_2=$ Atomic mass of $M$ $+$ $2$ $\times$ Atomic mass of chlorine

$120=M+2\left(35.5\right)$

$120-71=M=49$

Equivalent wt $=\frac{Molecularwt}{Valency}\Rightarrow \frac{49}{2}\Rightarrow 24.5$

Hence, option $C$ is correct.