Question

The percentage of an element $M$ is $53$ percentage in its oxide of molecular formula $M_2{O}_3$. Its atomic mass is about:

• A. 45
• B. 9
• C. 18
• D. 38
• E. 27

Answer 1

The correct option is E 27

Assume atomic mass of $M$ is $x$

Molecular weight of compound $=2x+16\times 3$

$=2x+48$

% of weight of M $=\frac{2x}{2x+48}\times 100=53\left(given\right)$

Solve for $x$,

$x=27.06=27$