Question

Write the standard line notation for each cell below.

IO3-(aq) + Fe2+(aq)--> Fe3+(aq) +I2(aq)
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H2O2 + 2 H+ + 2 e- --> 2 H2O E = 1.78 V
O2 + 2 H+ + 2 e- --> H2O2 E= 0.68 V
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Mn2+ + 2 e- --> Mn E = -1.18 V
Fe3+ + 3 e- --> Fe E = -0.036 V

Answer 1

Did you mean I2(s)? I think I2 usually is a solid so this would be a phase boundry and shown as I've done below. The () is where concns would go. You show aq there. You can write aq or the concn there. Here is a good site for reading.
http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Cell-Notation-and-Conventions-995.html
Pt, IO3^-(), Fe^2+()||Fe^3+()|I2, Pt