1) Solid, magnesium metal is reacted with aqueous phosphoric acid to generate magnesium phosphate and hydrogen gas.

3 Mg (s) + 2 H₃PO₄ (aq) --> Mg₃(PO₄)₂ (s) + 3 H₂ (g)

a) How many moles of hydrogen gas are generated if 315 mL of 1.22 M phosphoric acid is reacted with 7.95 g of magnesium metal?

b) If the gas produced in part (a) is collected in a 600 mL flask at 20.0 C, what is the pressure inside the flask?