There are three different forms of potential energy. The rock hanging above the ground has a form of stored energy called gravitational potential energy. This form of energy is due to the downward pull of Earth's gravity. ... When you stretch a rubber band, the elastic potential energy of the rubber band increases.
Balanced equation: 2Fe + 3H2O → Fe2O3 +3H2
Convert g to mols:
285/55.845 = 5.1034 mols
Mole ratio of Iron and Iron (III) Oxide: 2:1
5.1034/2 = 2.5517 mols