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Test 2 Q 7

Posted: Fri Mar 15, 2019 9:32 pm
by Katherine Grillo 1B
Why is the change in Gibbs free energy negative when ice melts? Isn't it gaining heat or in other words, isn't delta H positive?

Re: Test 2 Q 7  [ENDORSED]

Posted: Fri Mar 15, 2019 10:12 pm
by annabel 2A
Although deltaH is positive, deltaS is also positive (water is less orderly than ice), and deltaS*T is probably a greater value than deltaH which makes deltaG=deltaH-TdeltaS negative

Re: Test 2 Q 7

Posted: Sat Mar 16, 2019 1:23 pm
by taywebb
Because the outside environment is providing that heat directly, making this a naturally occurring reaction, no extra energy must be put in to make this reaction occur, so it is spontaneous.

Re: Test 2 Q 7

Posted: Sat Mar 16, 2019 4:39 pm
by Rehan Chinoy 1K
Just think about it conceptually -- the melting of ice is spontaneous in most temperatures, so deltaG should be negative.

Re: Test 2 Q 7

Posted: Sat Mar 16, 2019 6:00 pm
by Selina Bellin 2B
the situation is spontaneous bc there's nothing else that needs to be done to the ice in order to melt it

Re: Test 2 Q 7

Posted: Sat Mar 16, 2019 7:37 pm
by Jonathan Christie 1I
I was wondering how to come to this conclusion, thank you