Writing cell diagram

[Minh Ngo 4G]

So I have several questions regarding writing cell diagram
(I'm also refering to 6M.5:
For each reaction that is spontaneous under standard conditions (that is, K > 1), write a cell diagram, determine the standard cell potential, and calculate ΔG° for the reaction:
(a) 2 NO3 − (aq) + 8 H + (aq) + 6 Hg(l) → 3 Hg 2 2+ (aq) + 2 NO(g) + 4 H2O(l))
The answer for the cell diagram part is Hg (l)|Hg2 2+ (aq) ||NO3- (aq), H+ (aq)| O (g) | Pt(s)

1. When writing cell diagram, do we include liquids? If yes, why don't we include H2O?
2. Why there isn't any Pt(s) on the anode side? I thought that when there is no metal solid, you have to add eith Pt(s) or C(gr)?

[JonathanS 1H]

The answer to both questions is that Hg (l) is the anode in this case. With a liquid anode, we include the liquid but since water is our solvent and not involved in either the anode or cathode, we do not include it in the cell diagram.

[Minh Ngo 4G]

The answer to both questions is that Hg (l) is the anode in this case. With a liquid anode, we include the liquid but since water is our solvent and not involved in either the anode or cathode, we do not include it in the cell diagram.

So if the anode is in liquid state, we don’t need any metal?