ExamVeda
Login
Home

The rate constant of a chemical reaction increases by 100 times...

This question belongs to Chemical Engineering Chemical Reaction Engineering
Chemical Reaction Engineering
?

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

Answer & Solution
Correct Answer: Option B
Let's discuss the solution. Join the discussion
Examveda
Question posted by Examveda
Community

Join the Discussion

2 Comments
Ayan Murmu
Ayan Murmu 3 years ago
According to transition theory;

K = ko.T.e^-E/RT
And from this we get;
Ln(k2/k1) = ln(T2/T1) + E/R {1/T1 -1/T2};
As K2 = 100K1 T1=400k T2=500k;
Ln(100k1/k1) = ln(500/400) + E/R {1/400 - 1/500};
Solving this we get E/R= 8764K.
Chintan Bhalerao
Chintan Bhalerao 5 years ago
The answer given here i.e. 9210K is correct for Arrhenious law but by solving using Transition State theory we will end up with 8764K.
The equation for transition state theory is K = T*e^(E/RT)
so solving the same equation for two different point we end up with the following given equation:
ln(K2/K1) = ln(T2/T1) + E/R(1/T1 - 1/T2)
Putting all the values given in the question we end up with the answer option C i.e. 8764K
Thank You

Keep Learning

Related Questions on Chemical Reaction Engineering

A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and $${{\text{k}}_{\text{g}}}$$ respectively. The effective rate constant (keff) is given by
A. $${{\text{k}}_{\text{e}}}{\text{ff}} = {\text{k}} + {{\text{k}}_{\text{g}}}$$ B. $${{\text{k}}_{\text{e}}}{\text{ff}} = \frac{{{\text{k}} + {{\text{k}}_{\text{g}}}}}{2}$$ C. $${{\text{k}}_{\text{e}}}{\text{ff}} = {\left( {{\text{k}}{{\text{k}}_{\text{g}}}} \right)^{\frac{1}{2}}}$$ D. $$\frac{1}{{{{\text{k}}_{\text{e}}}{\text{ff}}}} = \frac{1}{{\text{k}}} + \frac{1}{{{{\text{k}}_{\text{g}}}}}$$
The half life period of a first order reaction is given by (where, K = rate constant. )
A. 1.5 K B. 2.5 K C. $$\frac{{0.693}}{{\text{K}}}$$ D. 6.93 K
Catalyst is a substance, which __________ chemical reaction.
A. Increases the speed of a B. Decreases the speed of a C. Can either increase or decrease the speed of a D. Alters the value of equilibrium constant in a reversible
A chemical reaction is of zero order, when the reaction rate is (where, CA = concentration of reactant)
A. $$ \propto {\text{CA}}$$ B. $$ \propto \frac{1}{{{\text{CA}}}}$$ C. Independent of temperature D. None of these
More Related Questions on Chemical Reaction Engineering