What is the percent yield? Check description for full question.

Question

If 0.45 grams of each reactant was used how much Zinc chloride would form? Zn + HCl --> ZnCl2 + H2 what is the percent yield if only .26 grams were recovered?

Answer 1

Zn(s) + 2HCl(aq) ==> ZnCl2(aq) + H2(g) ... balanced equation

moles Zn = 0.45 g Zn x 1 mol Zn/65 g = 0.0069 moles Zn

moles HCl = 0.45 g HCl x 1 mol HCl/37 g = 0.012 moles HCl

Since it takes 2 moles HCl per 1 mol Zn, the HCl is the LIMITING REACTANT (barely)...

Theoretical yield of ZnCl₂ = 0.012 mol HCl x 1 mol ZnCl₂/2 mol HCl x 136 g/mol = 0.82 g ZnCl₂

Percent yield = actual/theoretical (x100%) = 0.26 g/0.82 g (x100%) = 32% yield