Write the equilibrium reactions on a scratch paper, calculate k from ksp and kf and determine the concentration of nh3 needed to form 0.060 m ag(nh3)2+, kf = 1.6 x 107; ksp agcl = 1.77 x10-10

1) The equilibrium constant for the required reaction is .

2) 1.2474 M the concentration of ammonia needed to form 0.060 M of complex.Explanation:

Solubility product of silver chloride:

..(1)

Formation constant of :

..(2)

Reactions solid silver chloride and liquid ammonia:

Expression of an equilibrium constant of the above reaction can be written as:

[AgCl] = solid = 1

(from 1 and 2)

The equilibrium constant for the required reaction is .

2)

Concentration of complex at equilibrium : = 0.060 M

Initaly

                       x                         0              0  

At equilibrium

         x- 2(0.060)                      0.060              0.060

x = 1.2474 M

1.2474 M the concentration of ammonia needed to form 0.060 M of complex.