Beer-Lambert Law

The statement of the Beer-Lambert law can be written as follows: When a beam of monochromatic light is made incident on a solution that contains a substance that absorbs the monochromatic light, the rate at which the intensity of the beam decreases along the thickness of the solution is directly proportional to the concentration of the absorbing substance in the solution and is also directly proportional to the intensity of the incident monochromatic radiation.

As per the Beer-Lambert law, the greater the number of absorbing molecules (that have the ability to absorb light of a specific wavelength), the greater the extent of absorption of the radiation.

The Formula for Beeet-Lambert law:

A =log(I0/I )  = ecl

Where,

 A =absorbance 

I0 = intensity of light incident upon sample cell

I = intensity of light leaving sample cell 

c =molar concentration of solute 

l = length of sample cell (cm) 

e =molar absorptivity