Question

Hydrogen chloride decomposes to form hydrogen and chlorine, like this:

Answer 1

Solution :

Given :

Partial pressure of HCl, $P_{HCl}$ = 84.4 atm

Partial pressure of $H_2$, $P_{H_2}$ = 77.9 atm

Partial pressure of $Cl_2$, $P_{Cl_2}$ = 54.4 atm

Reaction :

$2HCl (g) \leftrightharpoons H_2(g) + Cl_2(g)$

Using equilibrium concept,

$k_p=\frac{(P_{H_2})(P_{Cl_{2}})}{(P_{HCl})^2}$

$k_p=\frac{77.9 \times 54.4}{(84.4)^2}$

$k_p=0.594$

$k_p=0.59$  (in 2 significant figures)

or $k_p=5.9 \times 10^{-1}$