Neet Solved Paper 2015 Question 15
Question: The activation energy of a reaction can be determined from the slope of which of the following graphs?
Options:
A) In $ K,vsT $
B) $ \frac{lnK}{T}vsT $
C) In $ Kvs\frac{l}{t} $
D) $ \frac{T}{\ln ,k}vs\frac{l}{T} $
Show Answer
Answer:
Correct Answer: C
Solution:
By Arrhenius equation $ K=A{e^{-E _{a}/RT}} $
where, $ E _{a} $ = energy of activation Applying log on both the side, $ \ln ,k=\ln A-\frac{E _{a}}{RT}\ $ …(i)
or $ \log ,k=-\frac{E _{a}}{2.303RT}+\log A, $ …(ii)
This equation is of the form of $ y=mx+c $ i.e. the equation of a straight line.
Thus, if a plote of $ \log k,vs\frac{1}{T} $ is a straight line, the validity of the equation is confirmed.
Slope of the line $ =-\frac{E _{a}}{2.303R} $
Thus, measuring the slope of the line, the value of $ E _{a} $ can be calculated.
