Solubility Equilibria Of Sparingly Soluble Salts

Step 1: Concept
Due to the common ion effect, the presence of

Cl%5E%7B-%7D

from NaCl will reduce the solubility of AgCl.
Step 2: Equilibrium Equations

AgCl%20(s)%20%5Crightleftharpoons%20Ag%5E%7B%2B%7D%20(aq)%20%2B%20Cl%5E%7B-%7D%20(aq)

Let solubility be

x

%5BAg%5E%7B%2B%7D%5D%20%3D%20x

and

%5BCl%5E%7B-%7D%5D%20%3D%20(x%20%2B%200.2)

.
Step 3: Calculation

K_%7Bsp%7D%20%3D%20%5BAg%5E%7B%2B%7D%5D%5BCl%5E%7B-%7D%5D%20%3D%20x(x%20%2B%200.2)

x

is very small,

(x%20%2B%200.2)%20%5Capprox%200.2

1.2%20%5Ctimes%2010%5E%7B-10%7D%20%3D%200.2x%20%5CRightarrow%20x%20%3D%206.0%20%5Ctimes%2010%5E%7B-10%7D%20M

.
Final Answer: (A)

Chapter Questions
1 MCQs