Beer–Lambert Law
The relation stating that absorbance is proportional to concentration and to the path length of the sample.
Formula / equation
A = ε c l
Unit
Dimensionless
In depth
The law holds for dilute solutions of a single absorbing species in monochromatic light. It fails at high concentration, where solute interactions change the absorptivity, and when stray light or chemical equilibria alter the absorbing species.
Examples in the real world
An absorbance of 0.60 in a 1 cm cell with ε = 6000 L/(mol·cm) indicating a concentration of 1.0 × 10⁻⁴ M.