Question

Assertion: The soap micelle is a negatively charged colloidal particle.

Reason: The negative charge on the micelle is due to the presence of OH⁻ ions of water.

Options

• If both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

• If both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

• If Assertion is correct but Reason is incorrect.

• If Assertion is incorrect but Reason is correct.

Answer 1

If Assertion is correct but Reason is incorrect.

Explanation:

The soap micelle is indeed a negatively charged colloidal particle because soap molecules dissociate into negatively charged RCOO⁻ ions, which form micelles with negative charge on the surface. However, this negative charge is not due to OH⁻ ions of water but due to the dissociation of soap molecules themselves into RCOO⁻ ions. Hence, the reason given is incorrect, as the negative charge originates from the soap molecules, not water hydroxide ions.