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Beer-Lambert Law:
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The Beer-Lambert Law describes the relationship between absorbance and concentration of a substance in solution. It states that absorbance is directly proportional to the concentration of the absorbing species and the path length of the light through the sample.
The calculator uses the Beer-Lambert Law equation:
Where:
Explanation: The equation calculates the concentration of a solution by dividing the measured absorbance by the molar absorptivity coefficient.
Details: Accurate concentration determination is essential in analytical chemistry, pharmaceutical analysis, environmental monitoring, and biochemical research for quantifying substances in various solutions.
Tips: Enter absorbance value (must be ≥0) and molar absorptivity (must be >0). Ensure measurements are taken at the appropriate wavelength and with proper calibration.
Q1: What is molar absorptivity?
A: Molar absorptivity (ε) is a measure of how strongly a chemical species absorbs light at a particular wavelength. It is a characteristic property of each substance.
Q2: What are typical absorbance values?
A: Absorbance values typically range from 0 to 2 AU. Values above 2 may indicate saturation and require sample dilution for accurate measurement.
Q3: When is the Beer-Lambert Law valid?
A: The law is valid for dilute solutions where the absorbing species do not interact with each other and when monochromatic light is used.
Q4: What affects absorbance measurements?
A: Factors include wavelength selection, path length, temperature, pH, solvent effects, and presence of interfering substances.
Q5: How do I determine molar absorptivity?
A: Molar absorptivity is typically determined experimentally by measuring absorbance of solutions with known concentrations and calculating ε from the slope of the calibration curve.