Concentration From Absorbance Calculator:
Enter the values of absorbance, A, path length, L(cm) and molar absorptivity, e(L/mol.cm) to determine the value of Concentration, C(mol/L).
Concentration From Absorbance Formula:
The concentration of a solute in a solution can be determined using the Beer-Lambert law, which relates the absorbance (A) of light passing through the
solution to the concentration (C) of the solute, the path length (L) of the light through the solution, and the molar absorptivity (e) of the solute at a specific wavelength.
The Beer-Lambert law is foundational in spectrophotometry, where light absorption is measured to infer the concentration of a substance in a solution.
The absorbance (A) is proportional to the concentration (C) of the solute, the path length (L), and the molar absorptivity (e), which is a constant for each solute at a given wavelength. The relationship between these parameters is crucial in fields such as chemistry, biochemistry, and environmental science for quantifying analytes in a solution.
- Absorbance is the measure of how much light is absorbed by the solution.
- Concentration refers to the quantity of solute dissolved in the solution.
- Path length is the distance that light travels as it passes through the solution.
- Molar Absorptivity is a constant that represents how strongly a substance absorbs light at a specific wavelength.
Concentration, C(mol/L) in mole per litre is found by dividing the absorbance, A by the product of the path length, L(cm) in centimetres and the molar absorptivity, e(L/mol.cm) in litre per mole centimetres.
Concentration, C(mol/L) = A / L(cm) * e(L/mol.cm)
C(mol/L) = concentration in mole per litre, mol/L.
A = absorbance.
L(cm) = path length in centimetres, cm.
e(L/mol.cm) = molar absorptivity in litre per mole centimetres, L/mol.cm.
Concentration From Absorbance Calculation:
- Given: A = 0.85, L(cm) = 1cm, e(L/mol.cm) = 2.5L/mol.cm.
Concentration, C(mol/L) = A / L(cm) * e(L/mol.cm)
C(mol/L) = 0.85 / 1 * 2.5
C(mol/L) = 0.34mol/L.
- Given: C(mol/L) = 0.5mol/L, L(cm) = 2cm, e(L/mol.cm) = 1.8L/mol.cm.
Concentration, C(mol/L) = A / L(cm) * e(L/mol.cm)
A = C(mol/L) * L(cm) * e(L/mol.cm)
A = 0.5 * 2 * 1.8
A = 1.8.