Home
Class 12
CHEMISTRY
The reaction Ararr X is a first order re...

The reaction A`rarr` X is a first order reaction which takes place in a vessel with initial concentration of A as 10 M. The rate constant for this reaction is 4.16`h^(-1)` . In the presence of a catalyst, the reaction A`rarr`Y follows second-order kinetics and the rate constant is 0.2 `min^(-1) M^(-1)` . What should be the initial concentration of A in the presence of catalyst so that the value of `t_(1//2)` for both the reactions is the same?

A

30.0 M

B

0.5 M

C

5.0 M

D

10.0 M

Text Solution

Verified by Experts

The correct Answer is:
B
(i) `A overset(k_(1))rarr X (k_(1) = 4.16 h^(-1) = 6.93 xx 10^(-2) "min"^(-1))` (ii) `A overset(k_(2))rarr Y (k_(2) = 0.2 "min"^(-1) M^(-1))`
Now, for (i) `t_(1//2) = (0.693)/(6.93 xx 10^(-2)) = 10 "min"` (for first-order reaction). It is independent of initial concentration. Also, for (ii) `t_(1//2) = (1)/(k a)` (for a second-order reaction) or `a = (1)/((0.2 "min"^(-1) M^(-1) xx 10 "min")) = 0.5 M`
Promotional Banner

Similar Questions

Explore conceptually related problems

In ____order reaction the rate of a reaction does not change with the concentration of the reactants.

For first order reaction half-life period Is Independent of initial concentration and Inversely proportional to the rate constant.Give relation for the above In the case of zero order reaction.

The rate constant for a first order reaction is 60 (s)^(-1) .How much time will it take to reduce the initial concentration of the reactant to its 1 / 16th value?

The rate constant of a reaction is 1.2xx10^-5s^-1 .The order of the reaction is _______.

The rate constant of a reaction at 298 K is given by 3.2xx10^(-3)s^(-1) .Find the order of reaction?

For a first-order reaction A rarr Products, the concentration of A changes from 0.1 M to 0.025 M in 40 min. The rate of the reaction when the concentration of A is 0.01 M is

In a first order reaction mathbf(A) rarr (B) if (k) is rate con stant and initial concentration of the reactant A. is 0.5 . M then the.half life is