Calculate the theoretical yield

Question

Calculate the theoretical yield of calcium chloride expected for this reaction if .80 mol of calcium hydroxide is reacted with excess hydrochloric acid.

Equation: Ca(OH)2+ 2HCl --> CaCl2 + 2H2O

Answer 1

The first step is to balance the equation. Ca(OH)₂ + 2 HCl →CaCl₂ + 2 H₂O, is in the balanced form.

The next step is to calculate the molecular weight. CaCl₂ contains one calcium and two chlorine atoms, which exhibit atomic weights of 40.08 and 35.45, respectively. The molecular weight of CaCl₂ is therefore (1 x 40.08) + (2 x 35.45) = 100.98.

Theoretical Yield is the amount of product that would have been produced if all of the limiting reagent reacted and it was 100% pure. The limiting reagent is used up first in a reaction and controls the amount of product that can be produced. 

Therefore, we will use straight mass-mass stoichiometry problem from the limiting reagent.

Mass CaCl2 = 0.8 mol Ca(OH)₂ x (1 mol CaCl₂ / 1 mol Ca(OH)₂) x (110.98g CaCl₂ / 1 mol CaCl₂) = 88.78 g CaCl₂