At 298 K the reaction A + B → products is carried out with B in large excess so that its concentration remains effectively constant. The concentration of A is monitored, and the results are given below.
Time, t (s) [A] (mol L⁻¹)
0.0 0.400
120 0.286
240 0.217
360 0.169
480 0.139
(1) Transform the concentration data so that a linear relationship with time is obtained. Show the numerical values that you generate and state which quantity is plotted on the vertical axis.
(2) Using an appropriate pair of transformed data points, determine the slope of the linear relationship and hence calculate the rate constant for the disappearance of A at 298 K. Be sure to report the correct units.
(3) Predict the concentration of A after 900 s under the same conditions. Show all mathematical steps leading to your answer.
(4) Evaluate whether the units of the rate constant you calculated are dimensionally consistent with the integrated rate law you employed. Provide a brief justification.