Question

Three experiments on the reaction A+B---> product, gave rise to the following raw data

Experiment	[A], M	[B], M	Rate, M/s
1	0.300	0.200	1.60 x 10^-3
2	0.300	0.400	2.26 x 10^-3
3	0.600	0.200	6.40 x 10^-3

a. Determine the rate law for the reaction.

Answer 1

Let rate law be   Rate = k [ A]^a [B]^b

where a, b are oder of reactions with repect to A and B respectively

exp 2 / exp1 gives us

2.26 x10^ -3 / 1.6x10^ -3 = k ( 0.3)^a ( 0.4)^b / ( k x 0.3^a x 0.2^b)

1.4125 = 2^b

b = log ( 1.4125) / ( log 2)

     = 0.5

exp 3/ exp1 gives us

6.4 x 10^ -3 / 1.6x10^-3 = k ( 0.6)^a ( 0.2)^b / ( k x 0.3^a x 0.2^b)

4 = 2^a

a = 2

now we input a, b values in rate q for exp 1

Rate = 1.6 x 10^-3 = k ( 0.3^2) ( 0.2)^0.5

k = 0.0126

now Rate law is

Rate = 0.0126 [A]^2 [B]^0.5                   where k = 0.0126