AbraCalc

Beer-Lambert Law: Absorbance 2.0, ε = 2000, 5 cm Path

Calculate Beer-Lambert concentration with absorbance 2.0, molar absorptivity 2000 L/mol·cm, and a 5 cm path length.

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How to use this tool

  1. Enter absorbance a, molar absorptivity ε, concentration c and path length l in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your absorbance a and the full breakdown beneath it.

This Beer-Lambert preset uses a longer 5 cm path length and moderate molar absorptivity to demonstrate the effect of path length on measured absorbance.

Frequently asked questions

What is molar absorptivity?
Also called the molar extinction coefficient (ε), it is a measure of how strongly a substance absorbs light at a given wavelength. Units: L/(mol·cm).
When does Beer-Lambert law break down?
At high concentrations (above ~0.01 mol/L) due to molecular interactions, or when the light source is not monochromatic.