If sufficient acid is used to react completely with 72.9 g of magnesium, how much hydrogen will be produced?

Question

If sufficient acid is used to react completely with 72.9 g of magnesium, how much hydrogen will be produced?

Answer 1

Mg + 2HCl ---->  MgCl2 + H2

1 mol Mg produces 1 mol H2

The molar mass of Mg is 24.3 g/mol

72.9 g Mg x ( 1 mol / 24.3 g) = 3.0 mol Mg

3.0 mol Mg x (1 mol H2 / 1 mol Mg) = 3.0 mol H2

3.0 mol H2 x (2.0. g / 1 mol ) = 6.0 g H2