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Question: The Arrhenius plots of two reactions, I and II are shown graphically. What does the graph suggest? ...

The Arrhenius plots of two reactions, I and II are shown graphically. What does the graph suggest?
(A) EI>EIIE_{I}>E_{II} and AI>AIIA_{I}>A_{II}
(B) EII>EIE_{II}>E_{I} and AII>AIA_{II}>A_{I}
(C) EII>EIE_{II}>E_{I} and AII>AIA_{II}>A_{I}
(D) EI>EIIE_{I}>E_{II} and AI>AIIA_{I}>A_{II}

Explanation

Solution

Arrhenius plot is a graphical representation of the logarithm of a reaction rate constant against the reciprocal of temperature.

Complete step by step answer
From Arrhenius plot we know that,
lnk=lnAEaRTln k= ln A -\dfrac{E_a}{RT}
Here the slope is,
EaRT\dfrac{E_a}{RT}

And the intercept is lnA

From the figure we can see that the slope and the intercept both are more for the graph I. Thus the activation energy and pre-exponential factor is more for I than II because they are directly proportional to each other.

Additional information:
Arrhenius plots are often used to analyse the effect of temperature on the rates of chemical reactions. The Arrhenius equation describes the relation between the rate of reaction and temperature for many physical and chemical reactions. lnk=lnAEaRTln k= ln A -\dfrac{E_a}{RT} is used to plot the graph and understand the reactions.

Note: In these types of questions we need to keep in mind that the activation energy and pre-exponential factor is directly proportional to the slope and the intercept of Arrhenius plot .