Electrochemistry

[Tony Ong 3K]

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]

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]

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]

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