Question

If 6 liters of hydrogen and 4 liters of chlorine are mixed and exploded and if water is added to the gases formed, find the volume of the residual gas.

Answer 1

1. 6 litres of hydrogen and 4 litres of chlorine when mixed, results in the formation of 8 litres ofHCl gas.
2. When water is added to it, it results in the formation of hydrochloric acid. Chlorine acts as a limiting agent leving behind only 2 litres of hydrogen gas.

 iii. Therefore, the volume of the residual gas will be 2 litres.

Answer 2

\[\ce{H2 + Cl2 -> 2HCl}\]
1 vol. 1 vol.      2 vol.
1 lit.   1 lit.        2 lit.

1 lit. of H₂ can use 1 lit. of Cl₂

∴ 4 lit. of H₂ can be combined with 4 lit. of Cl₂

\[\ce{H2 + Cl2 -> 2HCl}\]
6 lit.   4 lit.

1 lit of H₂ + 1 lit of Cl₂ = 2 lit of HCl

4 lit of H₂ forms 2 x 4 = 8 lit HCl

Hence after reaction 8 lit of HCl + 2 lit of H₂ i.e. 10 lit

When water is added to the gases formed HCl dissolves and residual gas is 2 lit. H₂·