As another example, consider the equilibrium between the following ions:

The formation of CoCl₄^2- is endothermic. On the heating, the equilibrium shifts to the left and the solution turns blue.

Cooling favours the exothermic reaction [ the formation of Co(H₂O)₆²⁺ ] and the solution turns pink

Le Chatelier / Le Chatelier's Principle

Changes in concentration  / Changes in volume & pressure / Summary