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Beer-Lambert Law:
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The Beer-Lambert Law describes the relationship between absorbance and the properties of the material through which light is passing. It states that absorbance is proportional to the concentration of the absorbing species and the path length of the light through the material.
The calculator uses the Beer-Lambert Law equation:
Where:
Explanation: The equation calculates the concentration of a solution based on how much light it absorbs, the substance's inherent ability to absorb light, and the distance the light travels through the solution.
Details: Accurate concentration determination is essential in analytical chemistry, pharmaceutical development, environmental monitoring, and various research applications where precise measurements of solute concentrations are required.
Tips: Enter absorbance (unitless), molar absorptivity in L/mol cm, and path length in cm. All values must be positive numbers greater than zero for accurate calculation.
Q1: What is the valid range for absorbance values?
A: Absorbance values typically range from 0 to 2 for accurate measurements. Values above 2 may indicate the solution is too concentrated and should be diluted.
Q2: How do I determine molar absorptivity?
A: Molar absorptivity is typically determined experimentally by measuring absorbance of solutions with known concentrations and using the Beer-Lambert Law.
Q3: What is the standard path length for cuvettes?
A: Standard cuvettes typically have a 1.0 cm path length, though other sizes (0.1 cm, 2.0 cm, etc.) are also available.
Q4: Does the Beer-Lambert Law have limitations?
A: Yes, it assumes monochromatic light, dilute solutions, and that absorbance is solely due to the analyte of interest without interactions between molecules.
Q5: Can this calculator be used for any wavelength?
A: Yes, but molar absorptivity is wavelength-dependent, so ensure you're using the ε value specific to the wavelength of measurement.