Question

Calcium hydride, CaH2, reacts with water to form hydrogen gas: CaH2 (s) + H20 (1) --> Ca(OH)2 (aq) + 2 H2 (g) This reaction is sometimes used to inflate life rafts when a simple, compact means of generating H2 is desired. How many grams of CaH2 are needed to generate 115 Lof H2 gas with a pressure of 815 torr at 19 °C? (MMCAH2 = 42.098 g/mol, MMH20 = 18.02 g/mol, MMCA(OH)2 = 74.098 g/mol, MMH2 = 2.02 g/mol)