Measuring Concentration

The Beer–Lambert law

An interactive lesson with 5 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A = log(I₀/I) = εcl.
• Each unit of A cuts the light tenfold.
• Calibration lines turn absorbance into concentration.

Steps

1. Darker means more
2. Slice the cuvette
3. Hit A = 0.50
4. Absorbance of 2
5. Read an unknown