Identify the limiting reagent.

Question

2.43g of magnesium is added to a solution containing 0.100 mol hydrochloric acid t ok produce hydrogen gas.

Answer 1

Mg + 2HCl ==>H2 + MgCl2
mols Mg = grams/molar mass
mols HCl = 0.100 mol

Using the coefficients in the balanced equation, convert mols Mg to mols H2.
Do the same for HCl.
In limiting reagent problems the limiting reagent is the one that produces the smaller mols of product.