An inexpensive hand warmer uses an exothermic chemical reaction to produce heat: iron reacts with oxygen to form ferric oxide, Fe₂O₃. Write a balanced chemical reaction for this oxidation process. Compute the energy liberated per kilogram of iron. Assuming that your hands each weigh about 0.4 kilogram and assuming that the specific heat of your hands is the same as water, what mass of iron would be needed to warm your hands from 10 ^◦C to body temperature,∼38 ^◦C?