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Percent Composition Calculator
Calculate the mass percent of each element in a compound
Formula: Percent Composition = (Total mass of element in compound / Molar mass of compound) × 100
Choose between entering a chemical formula or direct mass values.
Choose between entering a chemical formula or direct mass values.
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Calculation Results
⚠️ Percent composition by mass remains constant regardless of the sample size, governed by the Law of Definite Proportions. Ensure atomic weights and formula entries are accurate.