Question

When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and thus the reaction mixture becomes blue. On cooling the mixture it becomes pink. On the basis of this information mark the correct answer.
$\bigg[Co \underset{(Pink)}{(H_2O)_6}\bigg]^{3+} (aq) + 4Cl^- (aq) \rightleftharpoons\bigg [\underset{(Blue)}{CoCl_4}\bigg]^{2-} (aq) + 6H_2O(l)$
(a) $\Delta H$ > 0 for the reaction
(b ) $\Delta H$ < 0 for the reaction
(c ) $\Delta H$ = 0 for the reaction
(d) The sign of $\Delta H$ cannot be predicted on the basis of this information

Answer 1

the answer is option c

pls mark it as brainliest

Answer 2

Explanation:

on cooling, this means that the backward reaction is exothermic reaction. Therefore, the forward reaction is endothermic reaction and hence ΔH>0.