Ron reacts with hydrochloric acid to produce iron (II) chloride and hydrogen gas: Fe(s) + 2HCl(aq) => FeCl₂(aq) + H₂(g) The H₂ gas from the reaction of 2.2 g of iron with excess acid is collected in a 10.0-L flask at 25 °C. What is the pressure of the H₂ gas in this flask?