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J. W. Hill, R. H. Petrucci, T. W. McCreary, & S. S. Perry General Chemistry, 4th edition.

Problem 13.30.

Following are two statements pertaining to the reaction 2A + B 2C, for which the rate law is rate = k[A][B]. Identify which statement is true and which is false, and explain your reasoning.

(a) The value of k is independent of the initial concentrations [A]0 and [B]0.
(b) The unit of the rate constant for this reaction can be expressed either as s–1 or min–1.


The rate law is second order overall. The rate constant, by definition, is independent of concentrations, initial or otherwise, so (a) must be true. The units of the rate constant for a second order reaction are M–1s–1 or M–1min–1 (rate = Ms–1 = k[M][M]) so (b) is false.