Arrhenius Graphs

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Arrhenius Graphs

Postby Sanjay_Kumar_2J » Sun Mar 19, 2017 12:58 am

For an arrhenius graph, how do you calculate the Ea from the data given such as ln(K) and K-1?

Imani Johnson 1H
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Re: Arrhenius Graphs

Postby Imani Johnson 1H » Sun Mar 19, 2017 1:25 am

Idk if this is what you're asking but, From the 'progress of reaction' energy graph, the activation energy is the difference between the energy of the transition state and the reactants,I believe.

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Re: Arrhenius Graphs

Postby Azeel_Mohammed_1C » Sun Mar 19, 2017 2:32 am

"The rate constant of a reaction can be expressed as

k = Ae-Ea/RT

which is called the Arrhenius equation. Taking the natural log of both sides of the Arrhenius equation gives

ln k = -Ea/R(1/T) + ln A

The equation above is of the form y = mx + b, where y = ln k, m = -Ea/RT, x = 1/T, and b = ln A. For a reaction whose rate constant obeys the Arrhenius equation, a plot of ln k vs 1/T gives a straight line and it's slope can be used to determine Ea."

From there, it just depends the data you get and plug it into your equation.

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Re: Arrhenius Graphs

Postby Sarah_Kremer_1A » Sun Mar 19, 2017 12:13 pm

The slope of the line on the graph is equal to -Ea/R. Since R is a constant and you can find the slope using the data points, you can then find Ea.

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