Question

$0.622\text{g}$ of a metal carbonate on heating gives $0.466\text{g}$ of its oxide and some $C{O}_2$. Calculate the equivalent weight of the metal.

• A. $150.2\text{g}$
• B. $82.80\text{g}$
• C. $56.60\text{g}$
• D. $57.69\text{g}$

Answer 1

The correct option is D $57.69\text{g}$

Let the equivalent weight of the metal be denoted by $M$
Equivalent weight of carbonate ion $=C{O}_3^{2-}=30\text{g}$

$\frac{\text{weight of the metal carbonate}}{\text{weight of the metal oxide}}=\frac{\text{equivalent weight of the metal carbonate}}{\text{equivalent weight of the metal oxide}}$

$\Rightarrow \frac{0.622}{0.466}=\frac{M+30}{M+8}$

On solving, $M=57.69\text{g}$