Calculadora de Composição Percentual

The percent composition calculator determines the mass proportion of a component relative to the total mass of a mixture or compound, expressed as a percentage. The calculation is simple: divide the component's mass by the total mass and multiply by 100. For example, in a metal alloy with 80 g of copper and 20 g of tin, the percent composition of copper is (80/100) × 100 = 80%. This tool is useful for chemists, materials engineers, and students who need to check sample purity or adjust formulations.

It works based on the formula % = (m_comp / m_total) × 100. The user inputs the mass of the component and the total mass (or the masses of all components, which are automatically summed). The result shows the percentage of each part. It is important to ensure that masses are in the same unit (grams, kilograms, etc.) to avoid errors. The calculator does not consider chemical reactions or state changes, only mass relationships.

When to use? This calculator is ideal for routine analysis in chemistry labs, industrial quality control (e.g., checking the active ingredient content in a drug), preparing solutions with known mass concentration, and stoichiometry studies. It is also useful in chemistry classes to teach the concept of proportion. Avoid using it for molar concentration or volume calculations, as the formula is specific to mass.

Common precautions: Confusing component mass with total mass is the most frequent error. Always check that the total mass includes all components. Another caution: very small or large masses may require scientific notation. The calculator assumes the mixture is homogeneous and without losses. For substances with impurities, the percent composition may not reflect true purity, requiring a complementary analytical method.