Question

Equivalent wt.of a metal is $2.5$ times higher than oxygen. The ratio of weight of metal to the oxide is:

• A. $0.4$
• B. $1.4$
• C. $2.4$
• D. $3.4$

Answer 1

Answer: (A)

$0.4$

Solution:- (A) 0.4

Given that the equivalent weight of a metal is $2.5$ times higher than oxygen.

Equivalent weight of oxygen $=8$

$\therefore$ Equivalent weight of metal $=$ equivalent wt. of oxygen $+(2.5\times$ equivalent weight of oxygen) $=8+2.5\times 8=28$

As we know that $\text{eq. wt.}=\frac{\text{mol. wt.}\left(M_m\right)}{\text{valence factor}\left(n\right)}$

$\therefore$ Molecular weight of metal $\left(M_m\right)=28n$

Formula of metal oxide will be- $M_2{O}_n$

Molecular weight of metal oxide $=2\times M_m+n\times M_O=56n+16n=72n$

Ratio of weight of metal to its oxide $=\frac{\text{wt. of metal}}{\text{wt. of metal oxide}}=\frac{28n}{72n}=0.389\approx 0.4$

Hence the required answer is $\left(A\right)0.4$.