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 1.00-g sample of CaO is reacted with excess water and 0.82 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

The percent yield in this experiment is 63.1 %

Explanation:

To calculate the moles :

As is the excess reagent, acts as the limiting reagent and it limits the formation of product.

According to stoichiometry :

1 mole of produce = 1 mole of

Thus 0.018 moles of will produce=  of

Mass of

Theoretical yield = 1.3 g

Experimental yield of ethanol = 0.82 g

Thus the percent yield in this experiment is 63.1 %