In Mg+2HCI-->MgCl2+H2, how many grams of hydrogen can be produced when 6.00 g HCI is added to 5.00 g Mg?

Question

In Mg+2HCI-->MgCl2+H2, how many grams of hydrogen can be produced when 6.00 g HCI is added to 5.00 g Mg?

Answer 1

6.00 g HCl / 36.46 g/mol = 0.1646 mol HCl

5.00 g Mg / 24.32 g/mol = 0.2056 mol Mg

1 mol Mg requires 2 mol HCl

You have an excess of Mg

HCl is limiting

0.1646 mol HCl will produce 0.1646 / 2 or 0.0823 mol H2

0.0823 mol H2 x 2.016 g/mol = 0.166 g H2