Question

Illustrate Gay-Lussac's Law of combining volumes by referring to the reaction between :

(d) hydrogen and chlorine to form hydrogen chloride

Answer 1

Gay-Lussac's Law of combining volumes:

• According to this law, when gases react to form new gases, the ratio of the volume of gaseous reactants to the gaseous products is expressed as simple whole number ratio. The conditions required are constant pressure and temperature.
• This law is only applicable to gases. As a result, the volumes of solids and liquids are assumed to be zero.

Reaction between hydrogen $\left({\mathrm{H}}_2\right)$ and chlorine $\left({\mathrm{Cl}}_2\right)$:

• $1$ volume of hydrogen react with $1$volume of chlorine to form $2$ volumes of Hydrogen chloride $\left(\mathrm{HCl}\right)$ at the same pressure and temperature.
• The reaction is as follows:

$$\begin{gathered} {\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to 2\mathrm{HCl}\left(\mathrm{g}\right) \\ 1\mathrm{vol}1\mathrm{vol}2\mathrm{vols} \end{gathered}$$

• The ratio between the volumes of gaseous reactants and product is $1:1:2$. This is a simple whole-number ratio.