1. When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and the reaction mixture becomes blue. On cooling the mixture, it becomes pink. On the basis of this information mark the correct answer.
[Co(H20)6]2+ (aq) + 4Cl–(aq) [CoCl4]2-(aq) + 6H20(l)
(Pink) (Blue)
