Question

Describe the important electrical properties of colloidal solutions.

Answer 1

1. Charge on colloidal particles: Colloidal particles carry either a positive or negative charge, which causes mutual repulsion, helping them stay dispersed and preventing coagulation.
2. Electrophoresis: When an electric field is applied, charged colloidal particles move towards the electrode with the opposite charge. This movement confirms the presence of charge on particles.
3. Electro-osmosis: Under an electric field, the dispersion medium moves while colloidal particles remain stationary, typically when fixed by a membrane.
4. Coagulation by electric field: Applying a strong electric field (cataphoresis) can neutralize opposite charges on particles, causing them to aggregate and precipitate.