Question

A compound made up of two elements $A$ and $B$ is found to contain $25$% $A$ (atomic mass $=12.5$) and $75$% of $B$ (atomic mass $=37.5$). The simplest formula of the compound is:

• A. $AB$
• B. $A{B}_2$
• C. $A{B}_3$
• D. $A_{3}B$

Answer 1

The correct option is A $AB$

Let molecular formula be $A_x{B}_y$

Given compound contains $25$% $A\Rightarrow \frac{12.5x}{12.5x+37.5y}=\frac{1}{4}$

Given compound contains $75$% $B\Rightarrow \frac{37.5y}{12.5x+37.5y}=\frac{3}{4}$

$x=y=1$

$\therefore$ Compound is $AB$