(A) Hexamethylenediamine has the molecular formula C₆H₁₆N₂. It is one of the starting materials for the production of nylon. It can be prepared by the following reaction:

C₆H₁₀O₄(l) + NH₃(g) + H₂(g) → C₆H₁₆N₂(l) + H₂O(l) (not balanced)

A large reaction vessel contains 4.15 kg C₆H₁₀O₄, 0.547 kg NH₃, and 0.172 kg H₂. If 1.46 kg C₆H₁₆N₂ is obtained, then what is the percent yield for the experiment?

(B) Zinc metal and aqueous hydrochloric acid, HCl(aq), react to give hydrogen gas, H₂(g), and aqueous zinc chloride, ZnCl₂(aq). A 0.4000 g sample of impure zinc reacts completely when added to 750.0 mL of 0.0179 M HCl. After the reaction, the molarity of the HCl solution is determined to be 0.00403 M. What is the percent by mass of zinc in the sample?