Question

Assertion (A): Colloidal particles pass through ordinary filter paper.
Reason (R): Ultra filtration is a slow process.
Choose the correct option.

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is incorrect
• D. (A) is incorrect but (R) is correct

Hint:

Colloids pass through filter paper but not through semipermeable membranes used in dialysis.

Answer 1

The Correct Option is C

Step 1: Analyze Assertion (A).
Colloidal particles are very small (1–1000 nm) and can pass through ordinary filter paper because its pores are relatively large. Hence Assertion (A) is correct.

Step 2: Understand filtration behavior.
Ordinary filtration cannot separate colloids; only special methods like ultrafiltration or dialysis are used. This supports the correctness of (A).

Step 3: Analyze Reason (R).
Ultrafiltration being slow is true, but this statement does not explain why colloids pass through ordinary filter paper. So R is not the correct explanation.

Step 4: Identify logical link.
A describes particle size vs filter pore size, while R describes rate of ultrafiltration. They are unrelated concepts.

Step 5: Conclusion.
(A) is correct but (R) is incorrect as explanation.

Step 6: Final answer.
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