12. For the first order reaction a) The degree of dissociation is equal to (1-e-*¹) b)A plot of reciprocal of concentration of reactant v/s time gives a straight line c) The time taken for the completion of 75% reaction is thrice the half of reaction d) The time taken to complete 99.9% of the reaction is 10 times of half-life 13. In any unimolecular reaction the rato determin ston
Answers & Comments
Explanation:
The correct option (a) the degree of dissociation is equal to (1 - e-kt)
(d) the pre-exponential factor in the Arrhenius equation has the dimension of time, T-1
Explanation:
In first order reaction, if a is the degree of dissociation, therefore
k =1/t -loge 1/1-a
or kt = loge 1 (1-α) e-kt = 1- α -kr a=1-e = -log, (1-a)
or
Plot of reciprocal concentration of the reactant vs time is linear, for completion of 75% of reaction of first order, 2 x t1/2 time is required, for first order reaction dimensions of pre exponential factor 'A' are dimensions of ie, T-1.