stochimoetry problems help?

Question

How many grams of H2 will be produced when 1.00 g of Mg is added to a
250. mL sample of 0.500 M HCl?
Mg+2HCl--->MgCl2+H2

Answer 1

250. mL of 0.500 M HCl is 0.125 Mol of HCl.
1.00 g of Mg is 0.04114 Mol of Mg
Mg is the limiting reactant.
1 Mol of Mg would react and produce 1 Mol of H2
Hence 0.04114 Mol, or 0.0829 g, of H2 will be produced.