Enter the absorbance, concentration, and path length into the calculator to determine the molar absorptivity constant. This calculator helps in analyzing the results of spectrophotometric experiments.
Molar Absorptivity Constant Formula
The following formula is used to calculate the molar absorptivity constant.
ε = A / (c * l)
Variables:
- ε is the molar absorptivity constant (L/mol*cm)
- A is the absorbance (unitless)
- c is the concentration of the solution (M)
- l is the path length through which the light passes (cm)
To calculate the molar absorptivity constant, divide the absorbance by the product of the concentration and the path length.
What is Molar Absorptivity Constant?
The molar absorptivity constant, also known as the molar extinction coefficient, is a measure of how well a chemical species absorbs light at a particular wavelength. It is an intrinsic property of the substance and is used in Beer-Lambert law to relate the absorbance of a solution to its concentration and the path length of the cuvette in spectrophotometry.
How to Calculate Molar Absorptivity Constant?
The following steps outline how to calculate the Molar Absorptivity Constant.
- First, measure the absorbance (A) of the solution at the desired wavelength.
- Next, determine the concentration (c) of the solution in molarity (M).
- Then, measure the path length (l) of the cuvette in centimeters (cm).
- Use the formula ε = A / (c * l) to calculate the molar absorptivity constant (ε).
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Absorbance (A) = 0.5 (unitless)
Concentration (c) = 0.1 M
Path Length (l) = 1 cm
