question_answer 21)

The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks the following table :

Experiment	[A]M	[B]M	Initial rate of formation of
I	0.1	0.1
II	-	0.2
III	0.4	0.4	-
IV	-	0.2

 

Answer:

The rate equation is r = k [A]1 [B]0                                                      ?.. (i) From experiments I and II 2.0 x 10?2 = k[0.1]1[0.1]0                                         ?.. (ii) 4.0 x 10?2 = k [x]1 [0.2]0                                 ?.. (iii) Divide (iii) by (ii)   x = 2 x 0.1 = 0.2 M Thus, in experiments II, conc. of A is [A] = 0.2M. Now consider expeiments II and III. When conc. of A is doubled i.e. from 0.2 M to 0.4 M, the rate of the reaction is also doubled               Thus, the initial rate in experiment III is 8 x 10?2 M min?1. Now Consider experiment I and IV. Since the rate remains same and conc. Change of B does not affect the rate so conc. of A also remains the same i.e. [A] = 0.1 M.