# How do you measure concentration from absorbance?

Apr 3, 2014

The Beer-Lambert Law states that absorbance is equal to the product of concentration, path length and molar absorptivity, so if the latter two are known (or measured from a standard solution of known concentration) then the concentration of an unknown solution can be determined from its measured absorbance.

Here is a lab conducted to analyze a sample of iron(III) chloride using this concept.