Question

If 220 ml of 1 F AgNO2 is required to react quantitatively with 150 ml of KCN solution according to the reaction expressed by the equation Ag+ + 2CN- = Ag(CN)2-

Answer 1

0.03 moles of AgNO3

​will react with 2×0.03=0.06 moles of KCN to form 0.03 moles of [Ag(CN)2]

−Let x M be the silver ion concentration obtained due to dissociation of [Ag(

Here, 0.04>>x, 0.03>>x

The expression for the equilibrium constant is as shown below:

The equilibrium constant is equal to the reciprocal of the dissociation constant as the equilibrium reaction is the reverse of the dissociation reaction.

Substitute values in the above expressio

hence, x=7.5×10

−18

.