Calculate the theoretical max. yield of magnesium choride from the reaction of 100g of HCl with Mg, and calculate the percentage yield if an experiment produces 65g of MgCl

Question

Mg + 2HCl -> MgCl2 + H2

Answer 1

2HCl + Mg ==> MgCl₂ + H₂ ... balanced equation

Since we aren't given the amount of Mg, we can assume it is in excess and thus the theoretical max. yield of MgCl₂ will depend only on the amount of HCl present.

moles HCl present = 100 g HCl x 1 mol HCl / 36.5 g = 2.74 mols

theoretical moles MgCl₂ possible = 2.74 mols HCl x 1 mol MgCl₂ / 2 mol HCl = 1.37 mols MgCl₂

theoretical mass MgCl₂ possible = 1.37 mols xMgCl₂ x 95.2 g MgCl₂ / mol = 130 g MgCl₂

Percent yield = 65 g / 130 g (x100%) = 50% yield