The absorption coefficient (also known as molar absorptivity or molar extinction coefficient) for UV data can be calculated using the Beer-Lambert law, which relates the absorbance (A), concentration (C), path length (l), and absorption coefficient (ε) as follows:

A=ε⋅C⋅l

A is the absorbance of the sample.

ε is the absorption coefficient (molar absorptivity or molar extinction coefficient) with units of L/(mol·cm) or M⁻¹·cm⁻¹, depending on the concentration units.

C is the concentration of the absorbing species in moles per liter (Molarity, M).

l is the path length through which the light passes in centimeters (cm).it is remain constant 1 cm

To calculate the absorption coefficient (ε), you'll need to rearrange the Beer-Lambert equation as follows:

ε=A/C⋅l​

To calculate ε, you need to know the absorbance (A) of your sample at a specific wavelength, the concentration (C) of the absorbing species, and the path length (l) of the sample cell.

The result will have units of L/(mol·cm) or M⁻¹·cm⁻¹, depending on the units of concentration (C).

d=m/q.A (d is thickness (cm), m is cobalt oxide mass(gr), q is density of cobalt oxide (gr/cm3), A is surface area (cm2))

Rahul Mohonta , What is your definition of the absorption coefficient?" The thickness of what?

Fati̇h Ünal How "your" thickness relates the to the absorption coefficient?"

Balram Lohan Nice textbook's explanation, but it's not applicable for this case.

I am sorry. I thought you might know the relationship between absorption and absorption coefficient. absorption coefficient=2.303.A/d

A is absorbance, d is thickness. (Turkish Journal of Chemistry: Vol. 45: No. 6, Article 8.)

We have to follow IUPAC recommendations

Article Glossary of methods and terms used in analytical spectroscop...

6 absorbance, A

Logarithm of the division of incident radiant power (P0) by transmitted radiant power (Ptr).

52 experimental absorbance, A10

Decadic absorbance as measured with no corrections for other processes.

76 internal absorbance, Ai

Absorbance in the absence of reflection, scattering or luminescence.

77 internal absorptance, αi

Absorptance fully corrected for surface effects and effects of the cell, such as reflection, scattering, luminescence, and vignetting losses.

85 linear decadic absorption coefficient, a, K

decadic absorption coefficient

Decadic absorbance (A10) divided by path-length (l). a = A10/l.

92 molar decadic absorption coefficient, ε

Decadic absorbance (A10) divided by path-length (l) and amount concentration (c). ε = A10/(cl).

molar absorption coefficient

Fati̇h Ünal Compare your terminology with that of recommended by IUPAC