Final answer:
The integrated rate law for a first-order reaction is given by the equation
shows how the concentration of the reactant decreases exponentially over time, and can also be represented in logarithmic form.
Step-by-step explanation:
The integrated rate law for a first-order reaction relates the concentration of a reactant to the elapsed time of the reaction. This expression can be derived by integrating the first-order differential rate law, which is proportional to the concentration of the reactant (rate = k[A]). The result of this integration is an exponential equation:
is the concentration of the reactant at time t, [A]0 is the initial concentration, k is the rate constant, and t is the time elapsed. For analysis and plotting purposes, this equation can also be represented in logarithmic form as ln([A]) = ln([A]0) - kt. When ln([A]) is plotted against time, the result is a straight line for a first-order reaction, with the slope being -k.