Convert the grams of Li to moles: (34.2g)/(6.941 g/mol) = 4.927 moles of Li Looking at the balanced eqn:2 moles of Li react to give 1 mol of H2. Using the ratio 2:1,4.927 mol of Li will react to give 2.464 mol of H2. You have to use the ideal gas law now: PV=nRT to solve for the volume the 2.464 mol of H2 will occupy: PV=nRT(1.21)(v) = (2.464)(0.0821)(299) Solving for V algebraically, V=50.0L
