Percents

Based on the theory of chemical reactions, we expect a certain reaction to yield 402.6 g of a compound. We actually obtain 421.8 g. What was the percent yield? Is this possible?

Solution: 104.8% yield - Not possible

Sketch:

percent yield = actual / theoretical = 421.8 / 402.6 = 1.04769002.

This gives roughly 104.8%, which would indicate that we got more than was theoretically possible. This can not occur, so one of the numbers in the problem must be wrong, i.e., we must have made an error measuring one of the quantities or calculating the original theoretical yield!

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Developed by

Shodor
in cooperation with the Department of Chemistry,
The University of North Carolina at Chapel Hill

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Solution: 104.8% yield - Not possible Sketch:

Solution: 104.8% yield - Not possible

Sketch: