Use this Beer’s Law calculator to quickly determine the concentration of a solution based on its absorbance and the molar absorptivity coefficient.
How to Use the Beer’s Law Calculator:
To use the Beer’s Law Calculator, fill in any three of the four fields: Absorbance (A), Molar Absorptivity (ε), Path Length (l), and Concentration (C). Once you’ve entered the values, click the ‘Calculate’ button to obtain the result for the missing field. Ensure that you enter all but one field to get an accurate calculation.
How it Calculates the Results:
Beer’s Law is represented by the formula A = εlC, where A is the measure of absorbance, ε is the molar absorptivity with units of L/(mol*cm), l is the path length of the cell that contains the sample in cm, and C is the concentration of the compound in solution, expressed in mol/L (Molarity). The calculator solves for any one of these variables depending on which fields are provided using the same formula. If you enter Absorbance, Molar Absorptivity, and Path Length, it will calculate Concentration. Conversely, if you enter Molar Absorptivity, Path Length, and Concentration, it will calculate Absorbance.
Limitations:
It is crucial to remember that Beer’s Law is most accurate under conditions where the solution is dilute and the path length and molar absorptivity are constants. At very high concentrations, deviations can occur due to changes in the refractive index of the solution and the molecules’ interaction with each other. Always ensure that the values provided are within reasonable ranges and that the measurements are precise.