In the decomposition of azomethane at

2.18 10^4 pascals of pressure and a temperature of 576 K, the following concentration and time data were obtained:

t (min)

0

30

60

90

120

150

180

Concentration (mol/dm3)

8.7010^3

6.52 10 ^3

4.89 10 ^3

3.67 10 ^3

2.75 10 ^3

2.06 10 ^3

1.55 10 ^3

Show that the reaction is first order for azomethane and determine the rate constant at this temperature.