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Ch.19 - Free Energy & Thermodynamics

Chapter 19, Problem 49

Fill in the blanks in the table. Both ΔH and ΔS refer to the system.

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Hello everyone. So in this problem we are given a table and we're trying to complete the table this table. Maybe not really given to you by a professor or either found your textbook. It could be kind of scattered in your text and you can read that to fill this table. This is sort of like a really good review and kind of like a master key when we have different values for delta H, delta G. And tell it to us. So let's see here first row, we have a positive delta H. And a positive delta S. The delta G. That will depend on the temperature of as a negative or positive. Now, let's see if we have low temperature conditions, will this reaction be spontaneous? No, it will not. It will be non spontaneous. However, at high temperatures it will be spontaneous. So when the question is asking us that we have a positive delta H and a positive delta us, what conditions do they require to be spontaneous? It requires high temperatures. Now, moving on, what happens when we have a positive delta H. And a negative delta S. The sign for my delta G, then in that case would be positive. And because of that, if we have low temperature conditions, this is going to be non spontaneous. And also for high temperature conditions will also be non spontaneous. So whenever we have a direction that has a positive delta H, a negative delta S. No matter the temperature condition, it will still be non spontaneous. Moving on. What happens if we have a negative delta H and a negative delta S? What will be my delta G sign? That's going to be a positive DELTA G. And at low temperature conditions this reaction will be spontaneous and in high temperature conditions this reaction will be non spontaneous. So when a question asked that we have a negative DELTA H and a negative delta us, what conditions is required for it to be spontaneous? It will be under low temperature conditions. All right now, we see here, we have a positive delta S. And a negative delta jeep. What value do we need for our delta H? Then we're going to need a negative delta H value in that case. At low temperature conditions, this occurrence is going to be spontaneous. And then high temperatures there was reaction will also be spontaneous. So, if the problem is asking us under the condition which we have a negative delta age and a positive delta eight, sorry, a positive delta S. Then no matter what temperature condition that were given, it will always be spontaneous. So, let's go ahead and highlight all the answers that we have written. Alright, so all of those and highlighted, that's going to be my final answer for this problem. Thank you all so much for watching