Final answer:
The reaction described follows first-order kinetics, indicated by the linear relation in a plot of 1/[A] versus time. The rate constant, or k, can be found from the slope of this line, and its units are s^-1 for a first-order reaction.
Step-by-step explanation:
The reaction described is first-order, as indicated by the linear increase in a plot of one over the concentration of A versus time. For a first-order reaction, the integrated rate law is described by the equation [A] = [A]o e-kt, and taking the natural logarithm of each side gives a straight-line relationship between ln[A] and time. Since the plot of concentration versus time (concave upward) and the natural logarithm of concentration versus time also shows a decrease with time (concave upward), these are consistent with a first-order reaction.
The rate constant (k) can be determined from the slope of the plot of 1/[A] versus time, which is a straight line. The slope of this line is equal to k, and the rate constant can be found using any two points on this line.
As for units, in a first-order reaction, the rate constant k has units of s-1. This is because the rate law for a first-order reaction in terms of rate constant is rate = k[A], and since rate has units of M/s (molarity per second) and [A] has units of M (molarity), the units of k must be s-1 to balance the equation.