1. Assume that both 75 percent of the hydrogen gas can be recovered from the hydride and complete combustion of the hydrogen gas released, how much energy can be stored in a 3.5 kg sample of MgH2. Assume that water is in liquid state.
2. Coal reserves contain 3.87 x 10^16 moles of carbon. If efficiency is 40% how much gross energy can this produce by burning? Assume constant pressure.