J.R. S. answered 01/22/20
Ph.D. University Professor with 10+ years Tutoring Experience
2Al + 2OH- + 2H2O ==> 3H2 + 2AlO2-
0.150 g Al x 1 mol/26.98 g = 0.0055596 moles Al
0.0055596 moles Al x 3 mol H2/2 mol Al = 0.0083395 moles H2
PV = nRT
T = 50 + 273 = 323K
P = 750 mm/760 mm/atm = 0.9869 atm
V = nRT/P = (0.0083395)(0.0821)(323)/0.9868 = 0.224 L = 224 ml