Home
Back
Beer's Law Equation:
| From: | To: |
The molar absorption coefficient (ε) is a measure of how strongly a chemical species absorbs light at a given wavelength. It is a fundamental parameter in spectroscopy that quantifies the absorption characteristics of a substance according to Beer's Law.
The calculator uses Beer's Law equation:
Where:
Explanation: The equation describes the linear relationship between absorbance and concentration for a given path length and wavelength.
Details: The molar absorption coefficient is crucial for quantitative analysis in spectroscopy, determining unknown concentrations, characterizing compounds, and understanding molecular structure and electronic transitions.
Tips: Enter absorbance (unitless), concentration in mol/L, and path length in cm. All values must be positive and non-zero for accurate calculation.
Q1: What is the typical range for molar absorption coefficients?
A: Values typically range from 10 to 100,000 L/mol·cm, with higher values indicating stronger absorption. Values above 10,000 are considered high.
Q2: Does the molar absorption coefficient depend on wavelength?
A: Yes, ε is wavelength-dependent and should be specified at a particular wavelength for accurate comparisons.
Q3: What are the limitations of Beer's Law?
A: Beer's Law assumes monochromatic light, dilute solutions, and no chemical interactions. Deviations occur at high concentrations or with complex systems.
Q4: How is this different from extinction coefficient?
A: Molar absorption coefficient and molar extinction coefficient are often used interchangeably, both referring to ε in Beer's Law.
Q5: What factors affect the molar absorption coefficient?
A: Temperature, solvent, pH, and molecular structure all influence the value of ε for a given compound.