Question

Assertion :Diffusion is used in the enrichment of $U^{235}$. Reason: A lighter gas diffuses more rapidly than a heavier gas.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

$\underset{–}{\text{Graham's law of diffusion}}-$

It states that the rates of effusion/diffusion is inversely proportional to square root of mass of particles.

Graham's law of diffusion was the basis for separating $U^{235}$ and $U^{238}$ found in natural uraninite.

Graham's law $⟹r\propto \frac{1}{\sqrt{m}}$

As $m$ increases, rate decreases.

$⟹$ A lighter gas diffuses more rapidly than havier gas.