Question

Two oxides of an non-metal $X$ contain $50 \%$ and $40 \%$ of non-metal respectively. If the formula of the first oxide is $X O _{2}$. Then the formula of second oxide is

• A. $X _{2} O _{3}$
• B. $X_{2} O _{5}$
• C. $XO _{3}$
• D. $X_{2} O$

Answer 1

Answer: (C)

Given, Formula of first oxide is $X O _{2}$ means one mole of $X=2$ mole of oxygen in the first oxide.

For second Oxide $40 \%$ of $(X)$, we have $60 \%$ of oxygen.

i.e. For $40 \%$ of $(X)$, We have, $2 \times 60 \%$ of oxygen.

$\therefore $ For $100 \%$ of $(X)$ (i.e., one mole) we have, $\frac{2 \times 60}{40}=3$ moles of oxygen.

$\therefore $ Formula of second-oxide is $=X O _{3}$.