2hcl + mg mc031-1.jpg mgcl2 + h2 if 40.0 g of hcl react with an excess of magnesium metal, what is the theoretical yield of hydrogen?

1.10 g H₂

Explanation:

The reaction is

2HCl + Mg → MgCl₂ + H₂

An excess of magnesium metal means that the limiting reactant is HCl, so we use the mass of HCl given by the problem to calculate how many grams of H₂ are produced.

In order to make this calculation we need to keep in mind the molar mass of HCl, of H₂, and the reaction stoichiometry:

40.0 g HCl * 1.10 g H₂

wher is the rest of the question