Chapter 11, Problem 35QAP

Azomethane decomposes into nitrogen and ethane at high temperatures according to the following equation:

${\left({\text{CH}}_3\right)}_2{\text{N}}_2\left(g\right)\to {\text{N}}_2\left(g\right)+{\text{C}}_2{\text{H}}_6\left(g\right)$The rate of the reaction is followed by monitoring the disappearance of the purple color due to iodine. The following data are obtained at a certain temperature.

(a) By plotting the data, show that the reaction is first-order.

(b) From the graph, determine k.

(c) Using k, find the time (in hours) that it takes to decrease the concentration to 0.100 M.

(d) Calculate the rate of the reaction when $\left[{\left({\text{CH}}_3\right)}_2{\text{N}}_2\right]=0.415M$.