Question

Two elements A (At. wt 75) and B(At. wt 16) combine to yield a compound. The percentage by weight of 'A' in the compound was found to be 75.08 . The formula of the compound is:

• A. $A_{2}B$
• B. $A_2{B}_3$
• C. $AB$
• D. $A{B}_2$

Answer 1

The correct option is B $A_2{B}_3$

If percentage of A $=$ 75.08, then percentage of B $=$ 100 $-$ 75.08 $=24.92$

$\therefore$ Ratio in which A & B atoms are combining can be calculated as:

A:B $=\frac{75.08}{75}:\frac{24.92}{16}=1:1.5=2:3$

$\therefore$ Formula of the compound is $A_2{B}_3$.

Hence, option B is correct.