Question

X and Y are two compounds of elements $A$ and $Cl$. The molar mass and the mass % of $Cl$ are given in the table below.

$\begin{array}{ccc}\text{Compound}& \text{Molar mass}& \%\text{of Cl}\\ X& 200& 71\\ Y& 213& 50\end{array}$

X and Y are:

• A. $AC{l}_4,AC{l}_3$
• B. $A_{2}C{l}_3,AC{l}_3$
• C. $ACl,AC{l}_2$
• D. $AC{l}_3,AC{l}_5$

Answer 1

The correct option is A $AC{l}_4,AC{l}_3$

Let, X be $AC{l}_x\leftrightharpoons A^{x+}+xC{l}^{-},$
Y be $AC{l}_y\leftrightharpoons A^{y+}+yC{l}^{-}$

Molar mass of $X=200\text{g/mol}$
Molar mass of $Y=213\text{g/mol}$

% of $Cl$ in $X=\frac{35.5x}{200}=\frac{71}{100}$
on solving, $x=4.0$
% of $Cl$ in $Y=\frac{35.5y}{213}=\frac{50}{100}$
on solving, $y=3$

Thus, $X$ is $AC{l}_4$ and $Y$ is $AC{l}_3$