Answer:
The answer to your question is 19.7 g of MgCl₂
Explanation:
Data
mass of MgCl₂ = ?
mass of Mg(OH)₂ = 12 g
mass of HCl = 42 g
Balanced chemical reaction
Mg(OH)₂ + 2HCl ⇒ MgCl₂ + 2H₂O
Process
1.- Calculate the molar mass of the reactants
Mg(OH)₂ = 24 + 32 + 2 = 58 g
HCl = 1 + 35.5 = 36.6 x 2 = 72 g
2.- Calculate the theoretical yield
Mg(OH)₂ / HCl = 58 / 78 = 0.74
3.- Calculate the experimental yield
Mg(OH)₂ / HCl = 12 / 42 = 0.28
4.- Dertermine which is the limiting reactant
The limiting reactant is Mg(OH)₂ because the theoretical yield was lower than the experimental yield.
5.- Calculate the mass of MgCl₂
58 g of Mg(OH)₂ ------------------ 95 g of MgCl₂
12 g of Mg(OH)₂ ------------------ x
x = (12 x 95)/58
x = 19.7 g of MgCl₂
