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. underset"(pink)"([Co(H_2O_6)]_((aq))^(3+) + 4Cl_((aq))^(-) hArr underset"(blue)"([CoCl_4]_((aq))^(2)) + 6H_2O_((l))

When hydrochloric acid is added to cobalt nitrate solution at room tem

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. underset"(pink)"([Co(H_2O_6)]_((aq))^(3+) + 4Cl_((aq))^(-) hArr underset"(blue)"([CoCl_4]_((aq))^(2)) + 6H_2O_((l))
Answer» `DeltaH GT 0` for the reaction `DeltaH lt 0` for the reaction `DeltaH=0` for the reaction The sign of `DeltaH` cannot be PREDICTED on the basis of this information. Solution :In the reaction, `underset"(pink)"([Co(H_2O_6)]_(aq)^(3+)) + 4Cl_((aq))^(-) hArr underset"(blue)"([CoCl_4]_((aq))^(2)) + 6H_2O_((l))` On cooling, the equilibrium shifts reverse DIRECTION or on heating, the equilibrium shifts forward direction. Hence, reaction is endothermic. i.e., `DeltaH gt 0`.