2 RT dP k (3 P.-P) dt dP/dt k 3 P.-P Obtain dP/dt from a graph at any value of (3 P. - P) and put in above equation to get k. Ex. 2465 : For first order irreversible reaction A - R+ S, the pressure variation of the reaction mixture is as follows: Time, min 2 P, mmHg 200 208 215 226 If the initial reaction mixture contains 40 mole % A and 60 % inerts, find the rate expression for this reaction. Solution. We are sunglied with 0 4 0