How many grams of hydrogen are produced from 3.7 grams of aluminum? (Al + H2SO4 --> Al2(SO4)3 + H2 )

Answer 1

2Al + 3H₂SO₄ ==> Al₂(SO₄)₃ + 3H₂ ... balanced equation

Use the stoichiometry of the balanced equation along with dimensional analysis:

3.7 g Al x 1 mol Al / 26.98 g x 3 mol H₂ / 2 mol Al x 2.0 g H₂ / mol H₂ = 0.21 g H₂ produced (2 sig. figs.)

[note: g Al cancel; mol Al cancel; mol H₂ cancel leaving g H₂]