Delta G and Delta H

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Emily Lo 1J
Posts: 50
Joined: Thu Sep 19, 2019 12:16 am

Delta G and Delta H

Postby Emily Lo 1J » Wed Feb 19, 2020 4:47 pm

On Q6B, how do you determine which process will have delta H and delta g be similar?

Kylie Lim 4G
Posts: 110
Joined: Sat Aug 17, 2019 12:15 am

Re: Delta G and Delta H

Postby Kylie Lim 4G » Wed Feb 19, 2020 6:34 pm

I don't know if this is right but using the equation deltaG = deltaH - TdeltaS, I assumed that G and H would be most similar at the smallest possible values of S. This means that the correct answer is A because solids -> solids have the lowest entropy.

Adam Kramer 1A
Posts: 103
Joined: Sat Aug 24, 2019 12:15 am

Re: Delta G and Delta H

Postby Adam Kramer 1A » Thu Feb 20, 2020 8:06 am

When entropy approaching 0, the value of TdeltaS is nearly 0, meaning Delta H is very very close to delta G, since the second term in the Gibbs Free Energy Equation goes to 0 and becomes less and less significant.

Rohit Srinivas 2D
Posts: 94
Joined: Wed Sep 30, 2020 9:52 pm

Re: Delta G and Delta H

Postby Rohit Srinivas 2D » Sun Jan 31, 2021 3:57 pm

You would have to find a scenario in which enthalpy is either very large and where entropy is very small (which the above replies have covered). This is because a large enthalpy value is not likely to be skewed too much by a change in entropy. So a large negative enthalpy would correlate to a large negative delta G unless entropy is large and negative.

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