Beer's Law, also known as the Beer-Lambert Law, is a fundamental law in spectroscopy that describes the relationship between the concentration of a substance and its absorbance.

 Beer's law, in spectroscopy, a relation concerning the absorption of radiant energy by an absorbing medium. Formulated by German mathematician and chemist August Beer in 1852, it states that the absorptive capacity of a dissolved substance is directly proportional to its concentration in a solution.

Beer's Law, also known as the Beer-Lambert Law, is a fundamental law in spectroscopy that describes the relationship between the concentration of a substance and its absorbance. It states that the concentration of a substance is directly proportional to its absorbance, which is determined by the following factors: 

Absorptivity: How much of a particular wavelength of light a substance absorbs 

Cell thickness: The distance the light travels through the sample 

Sample concentration: The concentration of the substance in the solution 

Beer's Law is used to determine the concentration of a substance in a solution by measuring its absorbance with a colorimeter or spectrophotometer. 

Beer's Law

What it states

The concentration of a substance is directly proportional to its absorbance

How it's used

To determine the concentration of a substance in a solution by measuring its absorbance

Limitations

The electromagnetic radiation should be monochromatic, the light beam should not be scattered, and the solution should be diluted

The Beer-Lambert Law is based on the assumption that the sample is homogeneous and non-scattering. Deviations from the law can be caused by instrumental errors, such as insufficient resolution or detector nonlinearity.