Massaprosentteina

Massaprosentteina, or mass percent, is a way to express the composition of a mixture by stating what fraction of the total mass comes from a given component. It is widely used in chemistry, materials science, and industry to describe solutions, alloys, formulations, and mixtures in a simple, comparable form. The value is dimensionless and is written as a percentage.

The definition is straightforward: if a mixture has a total mass m_total and a component with mass m_i, then the mass percent of that component is w_i% = (m_i / m_total) × 100%. The mass fraction w_i = m_i / m_total is the same quantity expressed without multiplying by 100.

Notes on interpretation: mass percent refers to mass, not volume or concentration in terms of molarity. While the mass of components is fixed (to within measurement precision), densities and volumes can change with temperature, so volume-based measures may differ from mass-based ones. Mass percent is typically determined gravimetrically by weighing the components or the final mixture.

Example: If a solution contains 5 g of solute in a total mass of 100 g, the mass percent of the solute is (5/100) × 100% = 5%.

Relation to other measures: mass percent is related to but not identical with mole fraction and molarity. It is often used for practical formulations in foods, cosmetics, pharmaceuticals, and materials testing, providing a straightforward way to specify composition without requiring molecular weights or concentrations.