Video: The effect of concentration on equilibrium: cobalt complex
In aqueous solution, the hexaaquacobalt(II) ion is pale pink. Addition of high concentrations of chloride ion results in the formation of the blue tetrachlorocobaltate(II) ion.[Co(OH2)6]2+(aq) + 4 Cl-(aq) ? [CoC14]2-(aq) + 6 H2O(l)