Cobalt Chloride Equilibrium: Influence of Concentration and Temperature

This demonstration illustrates LeChatelier’s Principle: If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change. Starting with a red-pink solution of aqueous cobalt (II) chloride, students observe color changes in an equilibirum system due to changes in concentration of chloride ions or cobalt (II) ions. Changes to the temperature of the equilibrium system will change the color of the solution.
Cobalt Chloride Equilibirum Overview Slide Demo


Common Ion Effect

The addition of concentrated hydrochloric acid to a saturated solution of sodium chloride causes solid sodium chloride to precipitate out.

Copper-Ammonia Complex

Copper chloride solution forms a pale blue precipitate then a deep blue solution as ammonia is added.
Copper Hydroxide

Le Chatelier's Principle - Copper Ion

A copper(II) chloride solution alternates between blue and green when ligand concentrations change.
Le Chatelier Green


© Copyright 2012 Email: Randy Sullivan, University of Oregon Chemistry Department and UO Libraries Interactive Media Group