Electrochemistry


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Tony Ong 3K
Posts: 63
Joined: Fri Sep 28, 2018 12:23 am

Electrochemistry

Postby Tony Ong 3K » Sun Mar 03, 2019 10:01 pm

a) The standard Gibbs free energy of formation of Ti3+(aq) is 215 kJ/mol at 25 degrees C. Calculate the standard
potential of the Ti3+/Ti couple.
b) Will Ti+ disproportionate in aqueous solution?

Why is the 215kj/mol switched to -215jk/mol in part a of this problem's solution?

LorenzoDuvergne3I
Posts: 60
Joined: Fri Sep 28, 2018 12:25 am

Re: Electrochemistry

Postby LorenzoDuvergne3I » Mon Mar 04, 2019 3:04 am

I think it has something to do with the fact that you are going from Ti3+ to Ti (Since standard potential is written in the form of reduction), so instead of forming Ti3+ you are returning it to its standard form and have to change the sign. Not sure though.

Mona El Masri 1F
Posts: 34
Joined: Fri Sep 28, 2018 12:20 am

Re: Electrochemistry

Postby Mona El Masri 1F » Mon Mar 04, 2019 10:30 am

If the sign is changed, you add the two values. If not, you do cathode-anode. I was told to never reverse the sign and just stick to cathode-anode.

Xingzheng Sun 2K
Posts: 62
Joined: Fri Sep 28, 2018 12:29 am

Re: Electrochemistry

Postby Xingzheng Sun 2K » Fri Mar 08, 2019 4:07 am

Because the actual reaction going on is the reverse of formation of Tl3+, resulting in the standard Gibbs Free energy being the opposite.


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