6M.5

[Emil Velasco 1H]

For each reaction that is spontaneous under standard conditions (that is, K . 1), write a cell diagram, determine the standard cell potential, and calculate deltaG for the reaction:
(a) 2NO32(aq)18H1(aq)16Hg(l)S

~~For the cell diagram, why would the right side only be balanced with Platinum vs the left? The solution manual showed: "Hg(l) | Hg2+(aq || NO3-(aq), H+ (aq) | NO(g) | Pt (s)"

~~Also, generally, when creating a cell diagram, would you just separate each section by the anode/cathode and put each part in their respective phase state? (s|g|aq || aq |g|s)

[Sebastian Lee 1L]

The reason why the left side (anode) doesn't have the platinum electrode is because Hg (l) is a special case in that it can also act as a conductor. In this case, a wire could be inserted into the mercury which would be able to become oxidized, losing two electrons and sending a current through the wire. Platinum is necessary on the reduction side since there are no solid cathodes that can conduct the electricity.

Yes, the convention for cell diagrams is to write anode || cathode. There is no real convention on how the reactants/products on either side should be ordered but usually galvanic cells will be written like you noted where solids are on the outside and aqueous on the inside.