[ CoCl 4]2- (a q) is blue in colour while [ Co ( H 2 O )6]2+ (a q) is pink. The colour of reaction mixture [ Co ( H 2 O )6]2+ (a q)+4 Cl -(a q) leftharpoons[ CoCl 4]2-(a q)+6 H 2 O (l) is blue at room temperature while it is pink when cooled hence

Question

[ CoCl 4]2- (a q) is blue in colour while [ Co ( H 2 O )6]2+ (a q) is pink. The colour of reaction mixture [ Co ( H 2 O )6]2+ (a q)+4 Cl -(a q) leftharpoons[ CoCl 4]2-(a q)+6 H 2 O (l) is blue at room temperature while it is pink when cooled hence (A) reaction is exothermic (B) reaction is endothermic (C) equilibrium will shift in forward direction on adding water to reaction mixture (D) cquilibrium will not shift in forvard dircction on adding water to equilibrium mixture.

Tardigrade Admin · Accepted Answer

As on cooling pink colour intensifies so reaction is shifting in backward direction, so reaction must be endothermic.

Q. [CoCl4​]2−(aq)​ is blue in colour while [Co(H2​O)6​]2+(aq)​ is pink. The colour of reaction mixture [Co(H2​O)6​]2+(aq)​+4Cl(aq)−​⇌[CoCl4​](aq)2−​+6H2​O(l)​ is blue at room temperature while it is pink when cooled hence

reaction is exothermic

reaction is endothermic

equilibrium will shift in forward direction on adding water to reaction mixture

cquilibrium will not shift in forvard dircction on adding water to equilibrium mixture.

As on cooling pink colour intensifies so reaction is shifting in backward direction, so reaction must be endothermic.