Question

The equivalent weight of an element is 4. Its chloride has a vapour density 59.25. Then what is the valency of the element?

Answer 1

Let valency of element be n and chloride be $MC{l}_n$
So, as equivalent weight of element is 4, it molar weight = 4n and molar weight of chloride = $4n+35.5\times n$
As vapour density of chloride =59.25 so, molar wt of chloride $=59.25\times 2$ ($SinceV.D.=\frac{M.m.}{2}$)
Hence $4n+35.5\times n=59.25\times 2$
$\Rightarrow n=3$