The colour of given reaction mixture is blue at room temperature. On
[Co(H2O)6]2+(aq.)+4Cl−⇌[CoCl4]2−(aq.)+6H2O
Pink Blue
cooling it becomes pink, this indicates that :
a. reaction is exothermic
b. reaction is endothermic
c. reaction shifts in forward direction on cooling
d. none of the above