Chemical Engineering - Chemical Reaction Engineering - Discussion


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

[A]. 8987°K
[B]. 9210°K
[C]. 8764°K
[D]. 8621°K

Answer: Option B


No answer description available for this question.

Suman said: (May 13, 2013)  
k = k0*e^-(E/RT).
K1 = k0*e^-(E/400R).
K1 = k0*e^-(E/500R).
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.

Shan Rana said: (Nov 15, 2013)  
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.

V V said: (Dec 17, 2014)  
Correct answer: C

As they ask to solve by transition state theory.

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

Surya said: (Mar 4, 2015)  
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.

Ajay said: (Apr 8, 2015)  
For transition state theory answer is C. While B is when we use Arrhenius equation.

Ranjan Yadav said: (Nov 14, 2016)  
Ln((100k1/k1)) = E/R[(500 - 400)/(500 * 400)].
E/R = 9210 KELVIN.

Parth said: (Nov 12, 2017)  
Correct Answer is 8764 k. Here we are calculating according to transition state theory, So formula is k = k0e-(E/RT)*T.

Srinath said: (Feb 23, 2018)  
C is the correct option. I also agree.

Muhammad Saleh said: (Sep 26, 2018)  
Here we can use ln k2/k1 = E/R (1/T1-1/T2).

Vishal Verma said: (Feb 19, 2019)  
Option (C) is correct when it is given to transition state theory.

Option (B) is correct if we have given to assume Arrhenius theory.

Mnnit said: (Aug 28, 2019)  
The Correct answer is C.

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