Question

Elements P and Q react to form a compound $P_x{Q}_y.R$ and P react to form $R_y{P}_z$. If $x=2y,z=3y$ and P is hydrogen. Identify the pair of compounds.

Answer 1

(i) In $P_x{Q}_y$, $P$ is Hydrogen atom. So valency of $P=1$

(Refer to Image 1)

It can be seen that valency of

$P=1\left(y\right)$

$\Rightarrow x=2y$

$\therefore x=2\times 1$

$\therefore x=2$

(Refer to Image 2). Compound can be $H_{2}O,H_{2}S...$

(ii) $z=3y$

$\therefore z=3\left(1\right)$

$\therefore z=3$

(Refer to Image 3)

$R$ must be element of group $13$ having valency $3$. Example:- $Al{H}_3,B{H}_3$ etc.