Finding Temperature Where Reaction is Spontaneous






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Abigail Urbina 1K
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Joined: Thu Jul 27, 2017 3:01 am

Finding Temperature Where Reaction is Spontaneous

Postby Abigail Urbina 1K » Sun Feb 11, 2018 8:50 pm

Why do we have to set delta G equal to zero when we are trying to find the temperature at which a reaction is spontaneous? I just find this a little confusing because I typically associate spontaneous reactions with negative values for delta G

Lucian1F
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Re: Finding Temperature Where Reaction is Spontaneous

Postby Lucian1F » Sun Feb 11, 2018 8:59 pm

If you find it where G=0, you can figure out exactly what the temperature needs to be greater than or less than depending on the entropy for the reaction to be spontaneous

Anna Li 2E
Posts: 21
Joined: Sat Jul 22, 2017 3:00 am

Re: Finding Temperature Where Reaction is Spontaneous

Postby Anna Li 2E » Sun Feb 11, 2018 10:05 pm

You can also think about it like hypothetically what if we did set deltaG to a negative number? For example, you set deltaG=-1 and find the T value, you could set deltaG to an even smaller negative number, (ie -0.000001) and get a different temperature value. And so forth and so forth, always using a different deltaG value. We set deltaG=0 because while that in itself is not spontaneous, it is the threshold that helps us determine the range of T values where deltaG is negative.

You can view T as being ≥ or ≤ of a certain number rather than being exactly equal to a number.


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