If 5.0 moles of HCl reacts with 5.0 moles of Zn, how many grams of ZnCl2 are produced?

Answer 1

The first thing to do in this problem would be to find the balanced equation for the reaction of hydrochloric acid and Elemental zinc. The equation is as follows: 2HCl + Zn ----> ZnCl₂ + H₂

Then then you must find your limiting reactant. So you take the 5 moles of hydrochloric acid and the five moles of zinc and use Stoichiometry to find the moles of zinc chloride produced. And in this case hydrochloric acid is the limiting reactant because it produces 2.5 moles of zinc chloride whereas zinc produces 5 moles of zinc chloride. So you will do your calculation using Hydrochloric acid moles converting to zinc chloride moles. Then you would take those 2.5 moles of zinc chloride produced by the limiting reagent hydrochloric acid and multiply that 2.5 moles X the molecular mass of zinc chloride. That quantity is 136.286 grams. So in this step you're converting moles of zinc chloride to grams of zinc chloride. Then in the final step take 2.5 X 136.286 and that gives you 340.715 grams of zinc chloride.