1.
For the reaction 2HI(g)H2(g)+I2(g)2\mathrm{HI}(g) \rightleftharpoons \mathrm{H}_2(g) + \mathrm{I}_2(g), the degree of dissociation (α\alpha) of HI(g)\mathrm{HI}(g) is related to equilibrium constant KpK_p by the expression