In Beer's law, which term represents the molar absorptivity?

In Beer's law, which term represents the molar absorptivity?

• A. Molar absorptivity (epsilon)
• B. Path length (b)
• C. Concentration (c)
• D. Absorbance (A)

Answer: (A)

Beer's law links how much light is absorbed to the inherent ability of the substance to absorb at a given wavelength and to how much solute and how far the light travels. The term that represents this inherent light-absorbing strength per mole is molar absorptivity, denoted by ε. In the equation A = εbc, ε is the constant that tells you how strongly one mole per liter of the substance absorbs light over a path length of one centimeter at that wavelength. Its units are L/(mol·cm), and it is dependent on the specific substance and the light’s wavelength, not on how much solute is present or how long the light path is. The path length and the concentration are the factors you adjust (b and c) that scale the absorbance together with ε. Absorbance itself is the measurable outcome, while ε is the intrinsic property describing the absorbent’s efficiency.

Beer's law links how much light is absorbed to the inherent ability of the substance to absorb at a given wavelength and to how much solute and how far the light travels. The term that represents this inherent light-absorbing strength per mole is molar absorptivity, denoted by ε. In the equation A = εbc, ε is the constant that tells you how strongly one mole per liter of the substance absorbs light over a path length of one centimeter at that wavelength. Its units are L/(mol·cm), and it is dependent on the specific substance and the light’s wavelength, not on how much solute is present or how long the light path is. The path length and the concentration are the factors you adjust (b and c) that scale the absorbance together with ε. Absorbance itself is the measurable outcome, while ε is the intrinsic property describing the absorbent’s efficiency.