Beer Lambert Law Calculator

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The intensity of the transmitted light I is a function of the thickness x of the absorption medium given as

**I = I**_{o} $e^{- \mu x}$_{}Here I_{o} is the intensity of incident light

$\mu$ is absorption coefficient

**Step 1 :**

**Step 2 :**

Beer Lambert law named after August Beer tells that about the absorption of a monochromatic light by a solute using the spectrometer. The intensity of a monochromatic light entering an absorbing medium decreases exponentially with the thickness as well as the concentration of the absorbing medium.

The intensity of the transmitted light I is a function of the thickness x of the absorption medium given as

$\mu$ is absorption coefficient

Beer Lambert law Calculator is a online tool to calculate the intensity of the transmitted light I. You just have to enter the given quantities and enter the unknown quantity as x in the block provided and get your answer instantly.

Read the given problem and note down the given quantities

Use the formula

I = I_{o} $e^{-\mu x}$

Where I is the intensity of transmitted light

I_{o} is the intensity of incident light,

$\mu$ is absorption coefficient,

x is depth of the absorbing medium

Substitute the values in above formula and get the unknown quantity.

A monochromatic light having the intensity of 2 mW is passed through the transparent glass of 5 cm thickness. Calculate its final intensity after passing through the medium having absorbtion coefficient of 5 cm

^{-1}.**Step 1 :**Given: Initial intensity Io = 2 mW, thickness x = 5 cm, absorbtion coefficient $\mu$ = 5 cm

^{-1}**Step 2 :**The final intensity is given by

I = Io $e^{-\mu x}$

= 2 mW $\times$ $e^{- 5 \times 5}$

= 2.778 $\times$ 10^{-11}mW/m^{2}.**Answer :**The final intensity I = 2.778 $\times$ 10

^{-11}mW/m^{2}.A torch light has the intensity of 20 mW passes the glass of 2 cm thickness. If the final intensity is 2 $\times$ 10

^{-7}W/m^{2}.Calculate the absorption coefficient.**Step 1 :**Initial intensity I

_{o}= 20 mW, thickness x = 2 cm, Final intensity I = 2 $\times$ 10^{-7}W/m^{2}**Step 2 :**The final intensity is given by

I = Io $e^{-\mu x}$

Hence absorption coefficient is

$\mu$ = $\frac{1}{x}$ $\frac{ln I}{ln I_o}$

= $\frac{1}{0.02}$ $\frac{ln 2 \times 10^{-7}}{ln 20}$

= 18.94 mW/m

^{2}**Answer :**Absorbtion coefficient $\mu$ is 18.94 mW/m

^{2}