• Le Châtelier’s principle for changes in concentration can be explained by the equilibrium law.

• The position of equilibrium corresponds to a maximum value of entropy and a minimum in the value of the Gibbs free energy.

• The Gibbs free energy change of a reaction and the equilibrium constant can both be used to measure the position of an equilibrium reaction and are related by the equation, ΔGᴏ = −𝑅T ln 𝐾

• Solution of homogeneous equilibrium problems using the expression for Kc.

• Relationship between ΔGᴏ and the equilibrium constant.

• Calculations using the equation

ΔGᴏ = −𝑅T ln 𝐾.

• The expression ΔGᴏ = −𝑅T ln 𝐾 is given in the data booklet in section 1.

• Students will not be expected to derive the expression ΔGᴏ = −𝑅T ln 𝐾.

• The use of quadratic equations will not be assessed.