You have to divide the pressure exerted by the air into two partial pressures: of the dry air and of the water vapor. Combining these two values gives you the parameter.
The metal conducts the heat, which makes cooking easier.
For each half reaction:
>Balance all except O and H
>Balance O using H2O
>balance H using H+
>balance charge using e-
Then multiply the half reactions to balance the e-
Add them back together
