integrated rate law and half life

Question

1. Consider again the decomposition of NO2 discussed in slides 39-41. the reaction is second order in NO2 with k= 0.543 l/Ms. If the initial concentration of NO2 in a closed vessel is 0.0500 M, what is the remaining concentration after 0.500 hr?
2. calculate t 1/2 for the decomposition of the insecticide described on slide 35. how long does it take for the concentration of the insecticide to reach one- quarter of the initial value?
3. the reaction of C4H9CL with water is a first order reaction. slide 12 shows how the concentration of C4H9CL changes with time at particular temperature. (a) from that graph, estimate the half life for this reaction. (b) use the half life from (c) to calculate the rate constant.

Answer 1

For question 1

The integrated rate law for a 2^nd order reaction is 1/[A]_t = kt + 1/[A]_o

1/[A]_t = (.543 l/Ms)(60 s/min)(60 min/hr)(.500 hr) + 1/.0500

1/[A]_t = 977.4 + 2 = 979.4

[A]_t = 1/979.4 = 1.02 x 10^-3 M

At the present time, questions 2 and 3 cannot be answered as there is no data provided.