Question

how many grams of calcium chloride can be prepared from 60.4 G of calcium oxide and 69.0 G of hydrochloric acid and a double displacement reaction?

Answer 1

Balanced equation: 
CaO + 2 HCl --> CaCl2 + H2O 
Calculate moles of each reactant: 
60.4 g CaO / 56.08 g/mol = 1.08 mol CaO 
69.0 g HCl / 36.46 g/mol = 1.89 mol HCl 

Identify the limiting reactant: 
Moles CaO needed to react with all HCl: 
1.89 mol HCl X (1 mol CaO / 2 mol HCl) = 0.946 mol CaO 
Because you have more CaO than that available, HCl is the limiting reactant. 

Calculate moles and mass CaCl2: 
1.89 mol HCl X (1 mol CaCl2 / 2mol HCl) X 111.0 g/mol = 105 g CaCl2