Chemical Kinetics · Question 42

array|c|c| [A]0/ mol L-1 & t1/2/min \ 0.100 & 200 \ 0.025 & 100 \ array For a given reaction R P, t1/2 is related to [A]0 as given in table. Given: 2 = 0.30 Which of the following is true? Choose the correct answer from the options given below:

1. A and C Only
2. A, B and D Only
3. A and B Only
4. C and D Only

Answer

(2) A, B and D Only

Solution

For an nth order reaction, t1/2 [A]0 1-n

200100 = ( 0.1000.025 )1-n

2 = 41-n

(1-n) 4 = 2 1-n = 0.300.60 = 12

n = 12 A is true.

B: t1/2 = k'[A]01/2; from the first row k' = 200 0.1 = 200 10

for [A]0 = 1 M, t1/2 = 200 10 min B is true.

C: The order is a characteristic of the reaction (its rate law); it does not change when the initial concentration is changed from 0.100 M to 0.500 M C is false.

D: t1/2 = 200 10 1.6 = 200 16

= 800 min D is true.

A, B and D are true.

Answer: (2)