The following data were obtained from the gas phase reaction

A + B 3C

carried out in a constant volume bomb equipped with a pressure gauge for monitoring the progress of the reaction.

Time, min	Total pressure, psig
0	59
110	64
170	67
260	69
390	72
610	75
1070	78

The bomb initially contains 30% A, 40% B and 30% inerts at 150C.

A. Find a first order irreversible rate expression for the data.

B. Comment on the suitability of the rate expression.