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Question
Explain a graphical method to determine activation energy of a reaction.
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Solution
The Arrhenius equation is given by
`k=Ae^((-E_a)/(RT))`
On taking logarithms of both sides, we get
`log_nk=log_nA-E_a/(RT)`
or
`log_10k=-E_a/(2.303RT)+log_10A`
`log_10k=-E_a/(2.303R) times (1/T)+log_10A`
The rate constant of a reaction is determined at various temperatures.
log10 k is plotted against the reciprocal of temperature. The graphical
representation is
The slope of the straight line graph is
`–(Ea)/(2.303R)`
from which the activation energy can be calculated.
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