Question

The reaction 2A + B + C → D + E is found to be first-order in A, second order in B and zero-order in C. What is the effect on the rate of increasing concentration of A, B, and C two times?

• A. 72 times
• B. 8 times
• C. 32 times
• D. None of these

Answer 1

The correct option is B 8 times

The reaction 2A + B + C → D + E is first-order in A, second in B and zero-order in C.

Thus the rate of the reaction, r = k [A]¹ [B]² [C]⁰. The overall rate of the reaction is of third order. Since the rate of reaction is independent of [C]; so A and B will only affect rate of reaction by a factor of (2 x 2²) = 8.

Hence, option B is correct.