Why AgCl dissolves in CH3NH2 solution?
Amines containing 1 to 4 carbon atoms are water soluble, and like MH3 they are weak bases. For example,
CH3NH2(aq) + H2O(l) CH3NH3+(aq) + OH-(aq)
The solubility product, Ksp, for AgCl is 1.6 x 10?10, now when it reacts with CH3NH2,there is formation of of soluble and stable complex ,i.e.,[Ag(NH3CH3)2]+, i.e.,
2 reactions involved:- The reaction for the solubility of a saturated solution of sparingly soluble salt AgCl
AgCl (saturated,sparingly soluble)Ag+(aq) +Cl-(aq) (1) , Ksp=[Ag+][Cl-]
The stability constant representing the formation of complex ,[Ag(NH3CH3)2]+,
Ag+(aq) + CH3NH3+(aq) [Ag(NH3CH3)2]+(aq), (2)
So, Ag+ is getting consumed to form a stable complex i.e.[Ag(NH3CH3)2]+and AgCl gets dissolved in CH3NH2 solution.