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?

Respuesta :

Answer: The percent yield in this experiment is 63.1 %

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} CaO=\frac{1.00g}{56g/mol}=0.018moles[/tex]

[tex]CaO(s)+H_2O(l)\rightarrow Ca(OH)_2(s)[/tex]

As [tex]H_2O[/tex] is the excess reagent, [tex]CaO[/tex] acts as the limiting reagent and it limits the formation of product.

According to stoichiometry :

1 mole of [tex]CaO[/tex] produce = 1 mole of [tex]Ca(OH)_2[/tex]

Thus 0.018 moles of [tex]CaO[/tex] will produce=[tex]\frac{1}{1}\times 0.018=0.018moles[/tex]  of [tex]Ca(OH)_2[/tex]

Mass of [tex]Ca(OH)_2=moles\times {\text {Molar mass}}=0.018moles\times 74g/mol=1.3g[/tex]

Theoretical yield = 1.3 g

Experimental yield of ethanol = 0.82 g

[tex]\%\text{ yield }=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100=\frac{0.82g}{1.3g}\times 100=63.1\%[/tex]

Thus the percent yield in this experiment is 63.1 %