Learn how to solve problems like this one with our expert tutor.

Solution: 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 1.50 g sample of CaO is reacted with 1.50 kg of water and 1.48 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?A. 99.0%B. 24.0%C. 2.16%D. 74.8%E. 101.2%

Problem

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 1.50 g sample of CaO is reacted with 1.50 kg of water and 1.48 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

A. 99.0%
B. 24.0%
C. 2.16%
D. 74.8%
E. 101.2%


Solution

We’re being asked to calculate the percent yield of Ca(OH)2 in the reaction of 1.50 g CaO with excess H2O. The balanced chemical equation is:

CaO(s) + H2O(l)  Ca(OH)2(s)


Recall that percent yield is given by:

%yield = actual yieldtheoretical yield x 100


We know the reaction produced 1.48 g Ca(OH)2; this is the actual yield of the reaction. To calculate the theoretical yield, we need to do the following:


Mass of CaO (molar mass of CaO)  Moles of CaO (mole-to-mole comparison)  Moles of Ca(OH)2 (molar mass of Ca(OH)2)  Mass of Ca(OH)2


Since H2O is in excess, we can simply ignore it in our calculations.

Solution BlurView Complete Written Solution