Answer:
I2(g)/I^-(aq)//H2 (g)/H^+(aq)
Step-by-step explanation:
Let us remember that in every redox reaction, a specie is oxidized and a specie is reduced.
This means that one specie looses electrons while the other species gains electrons.
Considering the overall reaction; H2 + I2 = 2 HI
Oxidation half equation;
H2 (g) ------> 2H^+(aq) + 2e
Reduction half equation;
I2(g) + 2e ------> 2I^-(aq)
Line notation;
I2(g)/I^-(aq)//H2 (g)/H^+(aq)