Cl2 (g) ⇌ 2 Cl (g)
The equilibrium constant (Kc) for this reaction is given by the expression:
Kc = [Cl]^2/[Cl2]
where [Cl] is the equilibrium concentration of chlorine free radicals and [Cl2] is the equilibrium concentration of chlorine molecules.
At a given temperature, the value of Kc determines the extent to which Cl2 molecules decompose into Cl free radicals. A higher Kc value indicates a greater tendency for Cl2 to dissociate, resulting in a higher concentration of Cl free radicals at equilibrium.
Factors that influence the value of Kc for the decomposition of Cl2 include temperature and pressure. In general, Kc increases with increasing temperature. This is because higher temperatures provide more energy to the Cl2 molecules, which allows them to overcome the activation energy barrier required for dissociation. As a result, more Cl2 molecules dissociate into Cl free radicals, leading to a higher equilibrium concentration of Cl.
On the other hand, pressure has a relatively small effect on the value of Kc for the decomposition of Cl2. This is because the reaction does not involve a significant change in the number of moles of gas. Therefore, changes in pressure do not significantly affect the equilibrium position of the reaction.
In summary, the decomposition of chlorine molecules to form chlorine free radicals is a temperature-dependent process that is governed by the equilibrium constant Kc. Higher temperatures favor the formation of Cl free radicals, while pressure has a relatively small influence on the equilibrium position of the reaction.
