Question

Consider the reaction, 2A + B → Products. When the concentration of B alone was doubled, the half-life did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is:

A. L mol⁻¹s⁻¹
B. unitless
C. mol L⁻¹s⁻¹
D. s⁻¹

Answer 1

The unit of the rate constant for this reaction is mol L⁻¹s⁻¹. When the concentration of A alone is doubled, the rate increases by two times, indicating first-order kinetics. When the concentration of B alone is doubled, the half-life does not change. The correct answer is option: C. mol L⁻¹s⁻¹

Step-by-step explanation:

The unit of the rate constant for this reaction is C. mol L⁻¹s⁻¹.

The given information suggests that the reaction is first order with respect to A and B. When the concentration of A alone is doubled, the rate of the reaction doubles, indicating first-order kinetics. The units for a first-order rate constant are reciprocal seconds (s⁻¹).

However, when the concentration of B alone is doubled, the half-life does not change. This suggests that B does not affect the rate of the reaction, and therefore, the units of the rate constant remain unchanged.