Question

For the reaction 2A+B→C, the initial rate was measured at several different reactant concentrations. From the tabulated data, determine the rate law for the reaction.

a) Rate = [A][B]
b) Rate = [A]^2[B]
c) Rate = [A][B]^2
d) Rate = [A]^2
e) Rate = [B]

Answer 1

The rate law for the reaction 2A + B → C is determined to be rate = k [A] [B], showing it is first order with respect to each reactant (A and B), making (a) the correct answer.

Step-by-step explanation:

To determine the rate law of the reaction 2A + B → C, we can utilize the method of initial rates. This approach observes how changes in the concentrations of reactants affect the initial reaction rate. For the given reaction, it has been experimentally determined that doubling the concentration of A alone, or B alone, results in a doubling of the reaction rate. This implies that the reaction is first order with respect to both A and B. Accordingly, the rate law that reflects this dependence on reactant concentrations is: rate = k [A] [B]

Each of the reactants contributes in a linear fashion to the reaction rate, indicating they are both first-order with respect to the rate at which they affect it. Hence, option (a) Rate = [A][B] is identified as the correct rate law for the reaction. By using experimental data and this determined rate law, one can also calculate the rate constant (k) for the reaction and thus fully characterize the kinetics of the reaction in question. Therefore, a) Rate = [A][B] is the correct answer.