Chemistry homework

Question

Calculate the moles of zinc chloride produced if 19g of zinc reacts with 19g magnesium chloride

Answer 1

Actually, there shouldn't be any zinc chloride produced because zinc is below magnesium in the activity series and so should not replace the magnesium.

Zn(s) + MgCl₂(aq) ==> no reaction. However, if you want to assume that a reaction DID take place, you could proceed as follows:

Zn + MgCl₂ ==> Mg + ZnCl₂

moles Zn present = 19 g x 1 mol Zn/65 g = 0.29 moles Zn

moles MgCl₂ present = 19 g x 1 mol/95 g = 0.2 moles MgCl₂

MgCl₂ is limiting so the moles of ZnCl₂ produced is limited by the 0.2 mol MgCl₂ present.

0.20 moles MgCl₂ x 1 mol ZnCl₂/mol MgCl₂ = 0.20 moles ZnCl₂