Question

Beer Lambert's law gives the relation between which of the following?

• A. Reflected radiation and concentration
• B. Scattered radiation and concentration
• C. Energy absorption and concentration
• D. Energy absorption and reflected radiation

Hint:

Beer-Lambert Law. Relates light absorbance to concentration and path length: \(A = \epsilon c l\). Absorbance \(A\) is directly related to the amount of light energy absorbed by the sample.

Answer 1

The Correct Option is C

The Beer-Lambert Law (or Beer's Law) is fundamental to absorption spectroscopy (like UV-Vis spectrophotometry)
It relates the attenuation (decrease in intensity) of light as it passes through a substance to the properties of that substance
Specifically, it states that the absorbance (A) of a solution is directly proportional to the concentration (c) of the absorbing species and the path length (l) the light travels through the solution
$$ A = \epsilon c l $$ where \(\epsilon\) is the molar absorptivity (a constant for a given substance at a specific wavelength)
Absorbance is defined as \( A = \log_{10}(I_0 / I) \), where \(I_0\) is the incident light intensity and \(I\) is the transmitted light intensity
The difference (\(I_0 - I\)) represents the light energy absorbed (or scattered/reflected, but the law primarily focuses on absorption)
Therefore, the law fundamentally relates the absorption of light energy to the concentration of the absorbing substance