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Beer-Lambert Law:
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The Beer-Lambert Law relates the absorption of light to the properties of the material through which the light is traveling. It states that there is a linear relationship between the concentration and the absorbance of the solution, which enables the determination of the concentration of a solution using spectrophotometry.
The calculator uses the Beer-Lambert Law equation:
Where:
Explanation: The equation shows that concentration is directly proportional to absorbance and inversely proportional to both molar absorptivity and path length.
Details: Accurate concentration determination is crucial in analytical chemistry, biochemistry, and pharmaceutical sciences for quantifying substances in solution, quality control, and research applications.
Tips: Enter absorbance (unitless), molar absorptivity in L/mol·cm, and path length in cm. All values must be positive numbers greater than zero.
Q1: What is the valid range for absorbance values?
A: For accurate results, absorbance values should typically be between 0.1 and 1.0. Values outside this range may lead to less accurate measurements.
Q2: How is molar absorptivity determined?
A: Molar absorptivity is typically determined experimentally by measuring absorbance of solutions with known concentrations at a specific wavelength.
Q3: Does the Beer-Lambert Law have limitations?
A: Yes, it assumes monochromatic light, dilute solutions, and that the absorbing species do not interact with each other. Deviations can occur at high concentrations.
Q4: What is the standard path length used in spectrophotometry?
A: The most common path length is 1.0 cm, though other path lengths (0.1 cm, 1.5 cm, etc.) are also used depending on the application.
Q5: Can this calculator be used for any wavelength?
A: Yes, but the molar absorptivity value must be specific to the wavelength at which the absorbance was measured.