Question

$X$ and $Y$ are two compounds of elements $A$ and $C l .$ Molar mass $\%$ of $Cl$

Compound	Molar mass	$\%$ of $Cl$
X	137	77.5
Y	208	85.1

Thus, $X$ and $Y$ are

• A. $ACl _{3}, ACl _{4}$
• B. $A _{2} Cl _{3}, ACl _{3}$
• C. $ACl , ACl _{2}$
• D. $ACl _{3}, ACl _{5}$

Answer 1

Answer: (D)

Let, $X$ be $ACl _{ x } \rightleftharpoons A + xCl$,

$Y$ be $ACl _{ y }= A + yCl$

Moles mass of $x=137$

$\%$ of $Cl$ in $X =\frac{35.5 x}{137}=\frac{77.5}{100}$

$x=3.0$

$\%$ of $Cl$ in $Y =\frac{35.5 y}{208}=\frac{85.1}{100}$

$\therefore \,\,\,y=5$

Thus, $x$ is $ACl _{3} . Y$ is $ACl _{5}$