Q7Engineering Chemistry
Question
2 marks
Q.7 Define Beer-Lambert Law.
Answer
The combined Beer-Lambert Law mathematically asserts that the absolute amount of monochromatic light physically absorbed by a transparent chemical solution is strictly directly proportional to both the exact molar concentration of the absorbing chemical species and the total physical path length of the light.
The Beer-Lambert law is the absolute fundamental governing physical principle utilized strictly in all quantitative spectrophotometric chemical analysis.
- = The absolute measured Absorbance (Optical Density).
- = The exact incident light intensity.
- = The exact transmitted light intensity.
- = The molar extinction coefficient (or molar absorptivity), a strict constant for a specific molecule at a specific precise wavelength.
- = The exact molar concentration of the absorbing solution.
- = The absolute physical path length of the sample cell (cuvette), usually strictly 1 cm.