Question

$0.5\text{kg}$ of a metal carbonate gives $0.28\text{kg}$ of its oxide on heating. The equivalent weight of the metal is:

• A. $20\text{g}$
• B. $25\text{g}$
• C. $40\text{g}$
• D. $30\text{g}$

Answer 1

The correct option is A $20\text{g}$

Mass of the metal carbonate $=0.5\text{kg}=500\text{g}$
Mass of the metal oxide $=0.28\text{kg}=280\text{g}$

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

$\Rightarrow \frac{500}{280}=\frac{M+30}{M+8}$

On solving, $M=20\text{g}$