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Beer-Lambert Law:
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The Beer-Lambert Law describes the relationship between the absorption of light and the properties of the material through which the light is traveling. It states that the absorbance of a solution is directly proportional to its concentration and path length.
The calculator uses the Beer-Lambert Law equation:
Where:
Explanation: The equation calculates the concentration of a solution by measuring how much light it absorbs at a specific wavelength, using known values for molar absorptivity and path length.
Details: Accurate molarity calculation is essential in analytical chemistry, biochemistry, and pharmaceutical sciences for determining solution concentrations, preparing standard solutions, and conducting quantitative analysis.
Tips: Enter absorbance as a positive number, molar absorptivity in L/mol·cm (specific to the compound and wavelength), and path length in cm (typically 1 cm for standard cuvettes). All values must be greater than zero.
Q1: What is the valid range for absorbance values?
A: For accurate results, absorbance should typically be between 0.1 and 1.0. Values outside this range may suffer from significant measurement errors.
Q2: How do I determine molar absorptivity?
A: Molar absorptivity is determined experimentally by measuring absorbance of solutions with known concentrations and plotting a calibration curve.
Q3: Why is path length important?
A: Path length affects the amount of light absorbed - longer path lengths result in greater absorbance for the same concentration.
Q4: Can this be used for mixtures?
A: For mixtures, additional measurements at different wavelengths and more complex calculations are needed to determine individual component concentrations.
Q5: What are common sources of error?
A: Common errors include stray light, improper blank correction, temperature variations, and deviations from the linear range of the Beer-Lambert Law.