A student investigates the hydrolysis of CH₃Br in water at 25 °C under conditions where the concentrations of all species except CH₃Br remain effectively constant. The measured concentration of CH₃Br at various times is recorded in the table below.
Time (s)
[CH₃Br] (M)
0
0.100
200
0.082
400
0.067
600
0.055
800
0.045
1000
0.037
Assume that the temperature remains constant throughout the experiment.
(a) Use the data to determine the order of the reaction with respect to CH₃Br. Clearly explain how the evidence supports your conclusion.
(b) Calculate the numerical value of the rate constant k with the correct units, based on your answer to part (a). Show all work.
(c) Determine the half-life for CH₃Br under the experimental conditions.
(d) Predict the time required for the concentration of CH₃Br to decrease to 0.020 M. Show your calculations.