A solution of CoCI_(2).6H_(2)O in isopropyl alcohol and water is purple. The color change to blue when we add

A solution of CoCI_(2).6H_(2)O in isopropyl alcohol and water is purpl

1.	A solution of CoCI_(2).6H_(2)O in isopropyl alcohol and water is purple. The color change to blue when we add
Answer» concentrated HCI `AgNO_(3)(aq.) both (1) and (2) none of these Solution :The purple color is due to the MIXTURE of `[Co(H_(2)O)_(6)]^(2+)` (pink) and `[CoCl_(4)]^(2-)` (blue): `[Co(OH_(2))_(6)]^(2+)+4Cl^(-)hArr[CoCl_(4)]^(2-)+6H_(2)O` When we add concentrated HCI, excess `Cl^(-)` shifts the equilibrium to the right (blue). ADDING `AgNO_(3)` (aq.) removes some `Cl^(-)` by PRECIPITATION of `AgCl(s)` and favours the reaction to the left (PRODUCES more `[Co(OH_(2))_(6)]^(2+)` and the resulting solution is pink.