PERCENT YIELD

~ compares the actual amount of product that you made (in an experiment) to the amount of
product you should have made

~ ACTUAL YIELD: amount of product that you made in an experiment

~ THEORETICAL YIELD: amount of product that you should have made (according to
calculations)

~ % YIELD = ACTUAL YIELD X 100

THEORETICAL YIELD

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EXAMPLE
What is the percent yield if a student makes 5.2 grams of carbon dioxide by decomposing 9.5 grams of aluminum bicarbonate?

___ Al(HCO₃)₃ à ___ Al₂O₃ + ___ CO₂ + ___ H₂O

ANSWER:
_2_ Al(HCO₃)₃ à ___ Al₂O₃ + _6_ CO₂ + _3_ H₂O

9.5 g ? g

* I am given the actual yield in the problem; I need to find the theoretical yield. *

9.5 g Al(HCO₃)₃ | 1 mole Al(HCO₃)₃ | 6 moles CO₂ | 44 g CO₂ = 6.0 g CO₂
| 210 grams | 2 moles Al(HCO₃)₃ | 1 mole CO₂

So, 6.0 g is the theoretical yield.

% yield = 5.2 g x 100 = 87 %
6.0 g

PRACTICE PROBLEM

What is the percent yield if a student produces 3.7 grams of water by reacting 7.5 grams of oxygen with excess hydrogen?

___ H₂ + ___ O₂ à ___ H₂O

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