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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 the concentration of an absorbing species is directly proportional to the absorbance and inversely proportional to the path length and molar extinction coefficient.
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 the molar extinction coefficient and path length.
Details: Accurate concentration determination is crucial in spectroscopy, chemical analysis, and biochemical assays. It allows researchers to quantify unknown concentrations of substances in solution.
Tips: Enter absorbance (typically between 0.1-1.0 for best accuracy), molar extinction coefficient (specific to the substance and wavelength), and path length (usually 1 cm for standard cuvettes). All values must be positive.
Q1: What is the ideal absorbance range for accurate measurements?
A: The most accurate measurements are typically obtained with absorbance values between 0.1 and 1.0. Values outside this range may be less reliable.
Q2: Where can I find molar extinction coefficients?
A: Molar extinction coefficients are substance-specific and can be found in chemical literature, databases, or sometimes on the product information sheet from chemical suppliers.
Q3: Does this law work for all concentrations?
A: The Beer-Lambert Law applies best to dilute solutions. At high concentrations, interactions between molecules can cause deviations from linearity.
Q4: What affects the accuracy of concentration measurements?
A: Factors include instrument calibration, solution purity, wavelength selection, temperature, and proper blanking of the spectrophotometer.
Q5: Can I use this for mixtures?
A: For mixtures, you need additional information or measurements at multiple wavelengths, as substances may absorb at the same wavelength.