Answer:
The answer to your question is 8.1 g of ZnCl₂
Step-by-step explanation:
Data
mass of ZnCl₂ = ?
mass of Zn = 7.0 g
mass of CuCl₂ = 8 g
Balanced chemical reaction
Zn + CuCl₂ ⇒ ZnCl₂ + Cu
Process
1.- Calculate the molar mass of the reactants
Zn = 65.4 g
CuCl₂ = 63.6 + (35.5 x 2) = 134.6 g
2.- Calculate the limiting reactant
theoretical yield CuCl₂ / Zn = 134.6/65.4 = 2.06
experimental yield CuCl₂ / Zn = 8/7 = 1.1
The limiting reactant is CuCl₂ because the experimental yield was lower than the theoretical yield.
3.- Use proportions to calculate the mass of ZnCl₂
molar mass of ZnCl₂ = 65.4 + (35.5 x 2) = 136.4 g
134.6 g of CuCl₂ ---------------- 136.4 g of ZnCl₂
8 g ---------------- x
x = (8 x 136.4) / 134.6
x = 8.1 g of ZnCl₂