Question

How is carbon dioxide gas prepared from metal carbonates?

Answer 1

Understand the concept:

Metal carbonates and metal hydrogen carbonates react with acids to form metal salts, carbon dioxide, and water, respectively.

For example, Sodium carbonate reacts with dilute HCl.

Explanation of a reaction:

There is a formation of sodium chloride salt, water, and the evolution of only carbon dioxide gas.

${\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{l}\right)\to 2\mathrm{NaCl}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\uparrow$

Test for the presence of carbon dioxide :

The reaction produces carbon dioxide, which on passing through lime water forms milky water due to the production of calcium carbonate (${\mathrm{CaCO}}_3$) as it passes through it;

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{S}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

Thus in this way carbon dioxide (${\mathrm{CO}}_2$) is formed from metal carbonates or bicarbonates.