trifärgindikator

A trifärgindikator, or trichromatic indicator, is a type of chemical indicator that can exhibit three distinct color changes depending on the pH of the solution. These indicators are typically mixtures of other pH indicators, carefully chosen and blended to produce a series of color transitions over a specific pH range. The exact composition and blending ratios determine the pH values at which each color change occurs.

Unlike single-component indicators that might show one distinct color change (e.g., from red to blue), a trifärgindikator can display a progression. For example, a solution might initially be one color, then change to a second color at a certain pH, and finally shift to a third color at a different pH. This allows for a more nuanced estimation of the solution's acidity or alkalinity.

The principle behind a trifärgindikator relies on the overlapping pH ranges of the individual indicator components. Each component has its own pH transition range where it changes color. By combining indicators with different, but complementary, transition ranges, the resulting mixture provides a broader and more detailed pH indication. These indicators are often used in titrations or general pH testing where a more precise measurement than a single indicator can provide is desired, but a pH meter is not readily available or necessary. The specific colors observed are dependent on the precise combination of indicators used.