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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 a solution is directly proportional to its absorbance and inversely proportional to its molar absorptivity.
The calculator uses the Beer-Lambert Law:
Where:
Explanation: The equation shows that concentration can be determined by dividing the measured absorbance by the molar absorptivity coefficient at a given wavelength.
Details: Accurate concentration determination is crucial in analytical chemistry, biochemistry, and pharmaceutical sciences for quantifying substances in solution.
Tips: Enter absorbance (typically between 0.1-1.0 for best accuracy) and molar absorptivity (specific to the substance and wavelength). Both values must be positive.
Q1: What is the valid range for absorbance values?
A: The Beer-Lambert Law is typically valid for absorbance values between 0.1 and 1.0. Values outside this range may require dilution or concentration of the sample.
Q2: Where can I find molar absorptivity values?
A: Molar absorptivity values are substance-specific and wavelength-dependent. They can be found in chemical literature, databases, or determined experimentally.
Q3: Does path length affect this calculation?
A: This calculator assumes a standard 1 cm path length. For other path lengths, the equation becomes c = A/(ε·l) where l is path length in cm.
Q4: What are common sources of error?
A: Common errors include stray light, chemical deviations, improper blanking, and exceeding the linear range of absorbance.
Q5: Can this be used for mixtures?
A: For mixtures, more complex calculations or spectroscopic techniques are needed to determine individual component concentrations.