Question

The absorbance of a $\mathbf{2}\mathbf{.}\mathbf{31}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{5}}\mathbf{M}$ solution of a compound is 0.822 at a wavelength of 266nm in a 1.00-cm cell. Calculate the molar absorptivity at 266nm.

Short answer

The Molar absorptivity$\epsilon$ at266nm is$35584{\mathrm{M}}^{-1}{\mathrm{cm}}^{-1}.$.

Step-by-step solution

Definition of Moral Absorbance.

A spectrophotometric unit indicates the light a substance absorbs with respect to length, usually the centimeter, and concentration, usual moles per liter.

The Molar Absorptivity.

The molar absorbance is given as,

$A=\epsilon \cdot c\cdot b$

Therefore,

$$\begin{gathered} \mathrm{\epsilon }=\frac{\mathrm{A}}{\mathrm{c}\cdot \mathrm{b}} \\ \mathrm{\epsilon }=\frac{0.822}{2.31\cdot {10}^{-5}\mathrm{M}\cdot 1\mathrm{cm}} \\ \mathrm{\epsilon }=35584{\mathrm{M}}^{-1}{\mathrm{cm}}^{-1} \end{gathered}$$