What mass of aluminum must be used to produce 5.00 L of H2 gas at STP. 2Al + 6HCl  2AlCl3 + 3H2

Question

g

g/mol

mol

L

L/mL

mol

Answer 1

This question is combining stoichiometry along with the concept of gases which states that "1 mole of any gas at STP occupies ~22.4 L. 1 mole of H₂= 22.4L at STP.

The balanced chemical equation given tells us that for every 2 mol of Al 3 mol of H₂ is produced {if not sure about this review stoichiometric calculations!!!}

The steps are : L H₂ → mol H₂ → mol Al → g Al

5.00 L H₂ *(1 mol H₂ ⁄ 22.4 L H₂ ) * (2 mol Al ⁄ 3 mol H₂ ) * (26.98 g Al ⁄ 1 mol Al) = 4.01 g Al



Note; If you use 27.0 as molar mass of Al answer is 4.02 g