100 ml of 2M HCl solution completely neutralises 10 g. of a metal carbonate. Then the equivalent weight of the metal is

Number of gram equivalent of metal carbonate = Number of gram equivalent of acid

$\frac{\mathrm{Wt}}{\mathrm{GEW}}=\frac{{\mathrm{V}}_{\mathrm{a}}{\mathrm{N}}_{\mathrm{a}}}{1000}$

$\frac{10}{\mathrm{GEW}}=\frac{100\times 2}{1000}$

$\mathrm{GEW} =\frac{1000\times 10}{100\times 2}=\frac{10000}{200}=50$

Eq Wt of metal carbonate = E _metal+  ${\mathrm{E}}_{{\mathrm{CO}}_3^{-2}}$

50 = E _metal +30

E _metal $=50-30=20$