Question

Explain the following term with a suitable example.

Dialysis

Explain the following term:

Dialysis

Answer 1

Dialysis is the process of removing dissolved impurities or ions (like electrolytes) from a colloidal solution by diffusion through a semipermeable membrane.

In this process, only small particles (like ions and molecules of impurities) can pass through the membrane, while colloidal particles cannot.

Example: When a colloidal solution of starch contains NaCl as an impurity, it can be purified by placing it in a dialyser (e.g., parchment bag or animal membrane) and immersing it in pure water. The Na⁺ and Cl⁻ ions diffuse out, leaving behind pure starch sol.