Question

What will be charge on colloidal solution when agno3 solution is added to ki solution?

Answer 1

When AgNO3 is added to a KI solution the following reaction takes place:-

KI + AgNO3( excess) → AgI + KNO3

In the above reaction since AgNO3 is added to the solution of KI ,I assume that AgNO3 is added in excess. Now after the formation of the collide (AgI) , the excess ions (Ag+, NO3-), will tend to adsorp on the surface of the colloid. When it comes to the question of which ion adsorps, we need to understand the concept of preferential adsorption of common ions ( common in colloid and in the medium). Thus since Ag+ is common, it adsorps on the surface of the colloid and makes the colloid POSITIVE