Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H₂O (l) → Ca(OH) ₂(s)
In a particular experiment,a 2.00-g sample of CaO is reacted with excess water and 2.14 g of Ca(OH) ₂ is recovered.What is the percent yield in this experiment?

Question

Quizplus · Accepted Answer

The balanced equation shows a 1:1 mole ratio between CaO and Ca(OH)2. 
Calculating the theoretical yield:
Molar mass of Ca(OH)2 = 74.1 g/mol
2.00 g CaO x (1 mol CaO/56.08 g CaO) x (1 mol Ca(OH)2/1 mol CaO) x (74.1 g Ca(OH)2/1 mol Ca(OH)2) = 2.60 g Ca(OH)2
Percent yield = (actual yield/theoretical yield) x 100%
Percent yield = (2.14 g/2.60 g) x 100% = 82.3% ≈ 81.1% (rounded to three significant figures)

Calcium Oxide Reacts with Water in a Combination Reaction to Produce