Chemistry Problem - Reaction Rates

AI Thread Summary
The discussion centers on calculating the rate increase of a chemical reaction when the temperature changes from 118 C to 128 C, given that the rate doubles when the temperature rises from 25 C to 35 C. The Arrhenius equation is suggested as the method to solve the problem, but initial confusion arises due to insufficient information. A participant clarifies that by determining the activation energy (Ea) using the known rate change and temperatures, the problem can be solved. The key takeaway is that the rate constant (k2) must be twice the initial rate constant (k1) when the rate doubles. Ultimately, the discussion concludes with a better understanding of how to apply the Arrhenius equation to find the desired rate increase.
Kawrae
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I know this isn't a physics problem, but it's driving me crazy because I can't figure it out.

>> The rate of a particular reaction doubles (2.0 X) when the temperature is increased from 25 C to 35 C. By what factor will the rate increase over the temperature interval of 118 C to 128 C? <<

I'm thinking I have to use the Arrhenius equation that says:
e^(k2/k1) = e^Ea/R(1/t1-1/t2)

But I'm not given all of the information I need to solve it, am I? I'm very confused... I read over the notes handed out in class and the section in the book that covers this topic and I still can't figure it out. :confused:
 
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this is not solvable unless you make some unrealistic assumtion..
 
Kawrae said:
I know this isn't a physics problem, but it's driving me crazy because I can't figure it out.

>> The rate of a particular reaction doubles (2.0 X) when the temperature is increased from 25 C to 35 C. By what factor will the rate increase over the temperature interval of 118 C to 128 C? <<

I'm thinking I have to use the Arrhenius equation that says:
e^(k2/k1) = e^Ea/R(1/t1-1/t2)

But I'm not given all of the information I need to solve it, am I? I'm very confused... I read over the notes handed out in class and the section in the book that covers this topic and I still can't figure it out. :confused:

Solve for Ea. You've got everything... k2/k1=2. you've got t1=25C and t2=35C (convert to K).


Then plug in Ea, t1=118C and t2=128C to solve for k2/k1 for the second situation.
 
Thanks I think I understand it now :smile: I was getting stuck with using k2/k1 being equal to 2... but since the rate is doubling, the k2 would have to be 2x larger. Thanks :D
 
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