Calcium hydride, CaH2, reacts with water to form hydrogen
gas:
CaH₂(s) + 2 H₂O(1) Ca(OH)2(aq) + 2 H₂(g)
This reaction is sometimes used to inflate life rafts, weatherb
balloons, and the like, when a simple, compact means of
generating H₂ is desired. How many grams of CaH₂ are
needed to generate 145 L of H₂ gas if the pressure of H₂ is
825 torr at 21 °C?