Question:

Which of the following statements about colloids is False?

Freezing point of colloidal solution is lower than true solution at same concentration of a solute

When silver nitrate solution is added to potassium iodide solution, a negatively charged colloidal solution is formed

Colloidal particles can pass through ordinary filter paper

When excess of electrolyte is added to colloidal solution, colloidal particle will be precipitated

Solution:

The correct option is (A). Colloidal particles are larger than the particles in a true solution and smaller than those in a suspension. They are large enough that they will not pass through a semi-permeable membrane. While they can pass through ordinary filter paper (as stated in option C), they cannot pass through ultrafilters. Option A claims that colloidal particles are so small that they can pass through ordinary filter paper, which is a simplification and not entirely accurate. Therefore, statement A is false because colloidal particles do pass through ordinary filter paper, but not semipermeable membranes.