In the following question, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices:

Assertion: An ordinary filter paper impregnated with colloidon solution stops the flow of colloidal particles .

Reason : Pore size of filter paper becomes more than the size of colloidal particle. .

Assertion is true but the reason is false.

The correct answer is option 3. Assertion is true but the reason is false.

The assertion states that an ordinary filter paper impregnated with collodion solution stops the flow of colloidal particles. This statement is true. When filter paper is impregnated with collodion solution, it forms a semi-permeable membrane. Colloidal particles are too large to pass through this membrane, so they become trapped, effectively stopping their flow.

However, the reason provided suggests that the pore size of the filter paper becomes larger than the size of colloidal particles, leading to the stoppage of colloidal flow. This reason is not accurate. In reality, the impregnation of filter paper with collodion solution creates a physical barrier that traps colloidal particles, regardless of the pore size of the filter paper. The pore size of the filter paper itself does not necessarily change significantly due to the impregnation with collodion solution.

Therefore, while the assertion is true, the reason provided is false. The correct explanation lies in the formation of a semi-permeable membrane by the collodion solution, which physically traps colloidal particles.