Question

Assertion: At high pressure, decomposition of ammonia on the catalyst surface is a first-order reaction.

Reason: At high pressure, on changing the reaction conditions, the concentration of ammonia on the surface of the catalyst does not change.
a. Both assertion and reason are true, and the reason is the correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the correct explanation of the assertion.
c. Assertion is true, but the reason is false.
d. Assertion is false, but the reason is true.

Answer 1

At high pressure, the decomposition of ammonia on the catalyst surface is a first-order reaction. However, the reason given is false as the concentration of ammonia on the surface of the catalyst can change. Therefore, the correct option is C.

Step-by-step explanation:

Based on the given information, at high pressure, the decomposition of ammonia on the catalyst surface is a first-order reaction. Under high pressure, increasing the pressure of the system favors the forward reaction that produces fewer total moles of gas, which is the formation of ammonia from nitrogen and hydrogen. This indicates that the assertion is true.

However, the reason given in the question is false. On changing the reaction conditions, the concentration of ammonia on the surface of the catalyst can change. The concentration of ammonia will decrease as it is collected from the equilibrium mixture during the process, which shifts the equilibrium right and increases the yield of ammonia. Therefore, the reason is not the correct explanation of the assertion.

Thus, the correct answer is c. Assertion is true, but the reason is false.