Question

An element $A$ (atomic mass = $75$) and $B$ (atomic mass = $25$) combine to form a compound. The compound contains $75$% $A$ by mass.The formula of the compound will be :

• A. $A_{2}B$
• B. $A_{3}B$
• C. $A{B}_3$
• D. $AB$

Answer 1

Answer: (D)

$AB$

Let the mass of compound be $100$ g.
$A$ $B$
$75$ g $25$ g
$1$ mole $1$ mole
Since, the atomic mass of $A$ is $75$ g while that of $B$ is $25$ g.
So, the compound is $AB(1:1)$.