Once students are comfortable with working out K_c from equilibrium concentrations, they can carry out their own experiment to determine these concentrations. Finding equilibrium concentrations from initial concentrations can be quite demanding and it's worth spending time on this to make sure that students understand what they're doing.

The equilibrium involving ethanol, ethanoic acid, ethyl ethanoate and water is a popular choice for finding a K_c value. Different groups of students can set up mixtures using differing concentrations of the four components.

The worked example below shows how students can use their experimental data to calculate a value for K_c.

[INSERT EU_02_ani]