Consider the following reaction: SO2Cl2 (g) ⇌SO2 (g) + Cl2 (g) A reaction mixture is made containing an initial [SO2Cl2] of 2.1*10-2 M. At equilibrium, [Cl2] = 1.1*10-2 M. Calculate the value of the equilibrium constant (Kc).

0.012

Explanation:

Let's consider the following reaction.

SO₂Cl₂ (g) ⇌ SO₂ (g) + Cl₂ (g)

We can find the concentrations at equilibrium using an ICE Chart.

SO₂Cl₂ (g) ⇌ SO₂ (g) + Cl₂ (g)

I 2.1 * 10⁻² 0 0

C - x + x + x

E 2.1 * 10⁻²-x x x

We know that the concentration of Cl₂ at equilibrium is 1.1 * 10⁻² M, so x = 1.1 * 10⁻² M.

The concentrations at equilibrium are:

[SO₂Cl₂] = 2.1 * 10⁻²-x = 2.1 * 10⁻² - 1.1 * 10⁻² = 1.0 * 10⁻² M

[SO₂] = [Cl₂] = x = 1.1 * 10⁻² M

The concentration equilibrium constant (Kc) is:

Kc = [SO₂] * [Cl₂] / [SO₂Cl₂]

Kc = 1.1 * 10⁻² * 1.1 * 10⁻² / 1.0 * 10⁻²

Kc = 0.012