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Calculating actual mass from yield
A student produced a salt by reacting copper carbonate with sulfuric acid.
The maximum theoretical mass of the salt that could be produced using 50 cm³ of the sulfuric acid is 12.5 g. The percentage yield of the salt is 92.8%.
\%text{ yield}=frac{text{mass of salt actually produced}}{text{maximum theoretical mass of salt that could be produced}}× 100
Calculate the mass of salt actually produced. Use the equation shown.
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Marking points
- 1 Uses the maximum theoretical mass and percentage yield in a valid calculation.
- 2 Final mass is 11.6 g.
Full-mark answer
mass produced = (92.8 ÷ 100) × 12.5 = 11.6 g
Why this answer loses marks
I multiplied the theoretical mass by the percentage without converting it.
Treat the percentage as a fraction before scaling the theoretical mass.