Enter the balanced chemical equation including states that describes the electrochemical cell that is represented by the cell notation as shown.

Pt(s) l H2O(l) l O2(g) l H+(aq) ll H+(aq), Cr2O72-(aq), Cr3+(aq) l Pt(s)

3 answers

2H2O ==> O2 + 4H^+ 4e
H^+ + Cr2O7^-2 + 6e ==> 2Cr^+3 + 7H2O

You can add the phases. Check my work.
Okay so the problem I had with this is like...I did't understand that when it was written say on the left of the double vertical line how you know

H2O --> O2 + H+

will it always be written in the order of how you write the reaction? or like could you also right it like

O2 + H+ --> h2o

or basically how do you know which species (H2), O2, and H+ are on the reactant/product side?
also shouldn't it be the coefficient of H^+ in the second equation be 14?