Introduction to Beer-Lambert Law
- Use a reading that introduces the Beer-Lambert Law and derives the expression for the law. It also includes several examples to show the application of the Beer-Lambert Law for absorbance of transmitted light in medium, under different conditions.
- Use chapter reading, "The Beer-Lambert Law" by LibreTextsTM, that introduces the topic of light transmittance through a medium and Beer-Lambert's Law (or the Beer–Lambert–Bouguer law).
- The law is attributed to Pierre Bouguer, August Beer and Johann Heinrich Lambert.
- Understand how light transmitted through a medium is affected by its concentration. Also, discuss the importance of the path length for light transmittance through a medium.
- Use the reading to derive an expression for the Beer-Lambert's Law.
- Ponder over the non-linear (exponential) relation between transmittance and concentration of medium. Thus, define its molar absorptivity or molar absorption coefficient or molar extinction coefficient (ε).
- As per the Beer-Lambert's Law, the intensity of light decreases from I0 to I as it passes through a solution of concentration c and length/thickness l.
- Use the examples given in the text, to practice how to use the Beer-Lambert's Law to calculate values for the concentration, pathlength, and molar absorptivity of a given medium.
The graphic demostration of Beer-Lambert Law
Pierre Bouguer, a French mathematician, geophysicist, geodesist, and astronomer (1698-1758)
Johann Heinrich Lambert, a Swiss polymath (1728-1777)
Reading by LibreTextsTM