Chemistry · Grades 8–11
Mass percentage
Use total solution mass in the denominator: solute plus solvent. Multiply the fraction by 100.
Rule and assumptions
Use total solution mass in the denominator: solute plus solvent. Multiply the fraction by 100.
mass % = solute mass / solution mass × 100
Worked examples
A model solution contains 27 g solute and 171 g solvent. Find the solute mass percentage. Round to 3 decimal places if needed. Answer in %.
mass % = solute mass / solution mass × 100 27/(27 + 171) × 100 = 13.636
13.636 %
A model solution contains 35 g solute and 90 g solvent. Find the solute mass percentage. Round to 3 decimal places if needed. Answer in %.
mass % = solute mass / solution mass × 100 35/(35 + 90) × 100 = 28
28 %
Try two questions
A model solution contains 12 g solute and 328 g solvent. Find the solute mass percentage. Round to 3 decimal places if needed. Answer in %.
A model solution contains 14 g solute and 65 g solvent. Find the solute mass percentage. Round to 3 decimal places if needed. Answer in %.
Answers and reasoning
Answers and marking notes
- 3.529 %
mass % = solute mass / solution mass × 100 12/(12 + 328) × 100 = 3.529
- 17.722 %
mass % = solute mass / solution mass × 100 14/(14 + 65) × 100 = 17.722
Further reading and review references
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Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.