Percent Composition Calculator
Mass percent of each element, or of a solute in a solution.
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Results
- Percent composition
- 27.2921 %
- Mass contributed
- 12.011 g
- Remaining mass
- 31.998 g (72.7079%)
Working
- 1Mass of element = 12.011 × 1 = 12.011
- 2Percent = 12.011 ÷ 44.009 × 100 = 27.2921%
Quick answer
Percent composition is the mass of a component divided by the total mass of the compound, times 100: % = (mass of part / total mass) × 100.
% composition = (mass of element / molar mass of compound) × 100
How to use the Percent Composition Calculator
- 1Enter the atomic or molar mass of the element and how many atoms appear in the formula.
- 2Enter the molar mass of the whole compound.
- 3Read the mass percent.
Frequently asked questions
How do you find percent composition?
Divide the total mass of the element in one mole of the compound by the compound's molar mass, then multiply by 100.
What is the percent carbon in CO₂?
Carbon contributes 12.011 g/mol out of 44.009 g/mol, so CO₂ is 27.29% carbon by mass and 72.71% oxygen.