How to verify the Beer-Lambert Law?
How to verify the Beer-Lambert Law?
Answered
To verify the Beer-Lambert Law experimentally, prepare a series of standard solutions with known concentrations of the absorbing species and measure their absorbance at a fixed wavelength using a spectrophotometer. The absorbance values should be within a range that does not exceed the linearity limits of the spectrophotometer. Plot absorbance against the concentration of the standard solutions to create a calibration curve. If the Beer-Lambert Law holds, the plot should be linear with a slope equal to the product of the molar absorptivity (ε) and the path length (l). Deviations from linearity at high concentrations may indicate the presence of factors like molecular interactions, aggregation, or scattering that cause the law to fail under certain conditions. Verify that the plot remains linear for the concentrations of interest and ensure no other variables interfere with the measurement.
