Type of charge on Agl colloidal sol formed

When AgNO3 solution is added to KI solution, a white precipitate of AgI is formed. This precipitate can be separated by filtration, washed with water and then dispersed in water to form a colloidal sol. The type of charge on the AgI colloidal sol can be determined by considering the following factors:

Chemical reaction

AgNO3 + KI → AgI(s) + KNO3

The chemical reaction between AgNO3 and KI results in the formation of AgI precipitate. The AgI precipitate is insoluble in water and can be dispersed in water to form a colloidal sol. The AgI colloidal sol is formed due to the adsorption of AgI particles on the surface of water molecules.

Charge on AgI particles

The AgI particles in the colloidal sol are negatively charged. This is because when AgI is dispersed in water, it dissociates into Ag+ and I- ions. The Ag+ ions are adsorbed on the surface of water molecules and the I- ions are present in the solution. The negatively charged I- ions repel each other and prevent the AgI particles from coagulating.

Stabilization of colloidal sol

The AgI colloidal sol is stabilized by electrostatic repulsion between the negatively charged AgI particles. The repulsion between the particles prevents them from coming together and forming larger aggregates. The stability of the colloidal sol can be increased by increasing the surface area of the particles or by decreasing the interparticle distance.

In conclusion, the AgI colloidal sol formed by the addition of AgNO3 solution to KI solution has negatively charged AgI particles. This charge is due to the dissociation of AgI into Ag+ and I- ions, with the I- ions being present in the solution and causing the particles to be negatively charged. The stability of the colloidal sol is maintained by the electrostatic repulsion between the negatively charged particles.