Question

If $2.8\mathrm{g}$ metal oxide contains $0.8\mathrm{g}$ oxygen then the equivalent mass of metal is?

Answer 1

Step 1: Given data

Mass of metal oxide$=2.8\mathrm{g}$

Mass of oxygen$=0.8\mathrm{g}$

Step 2: Finding an equivalent weight

Mass of metal oxide$=$ Mass of the metal $+$Mass of oxygen

$2.8=\mathrm{x}+8$

$\mathrm{x}=$Mass of the metal$=2\mathrm{g}$

Now, $\mathrm{Equivalent}\mathrm{mass}=\frac{\mathrm{atomic}\mathrm{weight}}{\mathrm{valency}}$

Equivalent weight for oxygen$=\frac{16}{2}\Rightarrow 8\mathrm{g}$

$$\begin{gathered} \frac{\mathrm{Equivalent}\mathrm{mass}\mathrm{of}\mathrm{metal}}{\mathrm{Equivalent}\mathrm{mass}\mathrm{of}\mathrm{oxygen}}=\frac{\mathrm{Mass}\mathrm{of}\mathrm{metal}}{\mathrm{Mass}\mathrm{of}\mathrm{oxygen}} \\ \Rightarrow \frac{\mathrm{Equivalent}\mathrm{mass}\mathrm{of}\mathrm{metal}}{8}=\frac{2}{0.8} \\ \Rightarrow \mathrm{Equivalent}\mathrm{mass}\mathrm{of}\mathrm{metal}=\frac{2}{0.8}\times 8=20\mathrm{g} \end{gathered}$$

Therefore, the equivalent mass of metal$=20\mathrm{g}$