Chemical Engineering - Chemical Reaction Engineering - Discussion

Discussion Forum : Chemical Reaction Engineering - Section 1 (Q.No. 28)
28.
The rate constant of a chemical reaction increases by 100 times when the temperature is increased from 400 °K to 500 °K. Assuming transition state theory is valid, the value of E/R is
8987°K
9210°K
8764°K
8621°K
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
15 comments Page 2 of 2.

Ajay said:   1 decade ago
For transition state theory answer is C. While B is when we use Arrhenius equation.

Surya said:   1 decade ago
Here the answer is wrong the rate follows this equation according to transition state theory:

K = Ko*e^(-E/RT)*T.

Here k increased by 100 times and temperatures are 400 and 500 then we get the answer 8764.

V v said:   1 decade ago
Correct answer: C

As they ask to solve by transition state theory.

Equation is: K = Ko*e^(-E/RT)*T.

Shan Rana said:   1 decade ago
Correct option is [B] 9210K.

@Suman has given the right solution.

1/100 = e^(E/R400 - E/R500).
ln 0.01 = E/R (-1/2000).
-4.61 = E/R (-0.0005).
E/R = 4.61/0.0005.
E/R = 9210 K.
(1)

Suman said:   1 decade ago
k = k0*e^-(E/RT).
K1 = k0*e^-(E/400R).
K1 = k0*e^-(E/500R).
GIVEN THAT,
K2 = 100K1.................(1).
K1/K2 = e^-(E/400R-E/500R).........(2).

Substitute eqn 1 in 2 and take logarithmic on both sides you will get the answer.
(2)


Post your comments here:

Your comments will be displayed after verification.