Assertion: The decomposition of gaseous ammonia on a hot platinum surface is a zero order reaction at high pressure.
Reason: For a zero order reaction, the rate of reaction is independent of initial concentration.

Options

A. If both (A) and (R) are correct and (R) is the correct explanation of (A)
B. If both (A) and (R) are correct, but (R) is not the correct explanation of (A).
C. If (A) is correct, but (R) is incorrect.
D. If both (A) and (R) are incorrect.

Answer

B

Explanation

At high pressure, the metal surface gets saturated with gas molecules. So a further change in reaction conditions is unable to alter the amount of ammonia on the surface of the catalyst making rate of the reaction independent of its concentration.