Question

Two oxides of a metal contain $50$% and $40$% metal (M) respectively. If the formula of first oxide is $M{O}_2$, the formula of second oxide will be:

• A. $M{O}_2$
• B. $M{O}_3$
• C. $M_{2}O$
• D. $M_2{O}_5$

Answer 1

The correct option is B $M{O}_3$

$\text{Compound}150\%M+50\%O$

$\text{formula}M{O}_2$

Let atomic weight of metal be $X,$

$⟹M{O}_2:$ $\frac{16}{X}=\frac{1}{2}$

Hence atomic weight of metal $=32$

$\text{Compound}2:$ $40\%M=\frac{40}{32}=1.25=160\%O=\frac{60}{16}=3.75=3$

$\therefore$ Formula is $M{O}_3$.