3. The complex ion Co(H2O)6 2(aq) is pink when placed in solution. Addition of chloride ions creates an equilibrium with CoCl42- in the solution, which is blue in color. Write the balanced equation for the equilibrium. If CoCl42- solubility is endothermic, predict what will happen to the solution color if the solution is heated. What will happen if the solution is cooled

See explanation

Explanation:

When the complex ion Co(H2O)6 2+(aq) is placed in solution and chloride ions are added, the following equilobrium is set up;

  Co(H2O)62+(aq) + 4 Cl-(aq) <=> CoCl42-(aq) + 6 H2O(g)

Co(H2O)6 2+(aq) solution  is pink in colour while CoCl42-(aq) solution is blue in colour.

Since the solubility of CoCl42-(aq) is endothermic, heating the solution will move the equilibrium position towards the right (more CoCl42-(aq) is formed and the solution is blue in colour).

When the solution is cooled, more Co(H2O)62+(aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in colour.