Respuesta :
Explanation:
The given data is as follows.
[tex]\lambda[/tex] = 211 nm, [tex]\sum = 6.17 \times 10^{3} mol/L/cm[/tex]
l = 1 cm, 7% < Transmittance < 85%
Suppose the aqueous solution follows Lambert-Beer's law. Therefore,
Absorbance = [tex]-log \frac{\text{Percentage transmittance}}{100}[/tex]
Hence, for 7% transmittance the value of absorbance will be as follows.
Absorbance = [tex]-log \frac{7}{100}[/tex]
[tex]A_{1}[/tex] = 1.155
For 85% transmittance the value of absorbance will be as follows.
Absorbance = [tex]-log \frac{85}{100}[/tex]
[tex]A_{2}[/tex] = 0.07058
According to Lambert-Beer's law.
A = [tex]\sum \times l \times C[/tex]
where, A = absorbance
[tex]\sum[/tex] = molar extinction coefficient
C = concentration
Therefore, concentration for 7% absorbance is as follows.
[tex]A_{1} = \sum \times l \times C_{1}[/tex]
[tex]C_{1}[/tex] = [tex]\frac{1.155}{6.17 \times 10^{3} \times 1}[/tex]
= [tex]0.187 \times 10^{-3} mol/L[/tex]
= 0.187 mmol/L
Concentration for 85% absorbance is as follows.
[tex]A_{2} = \sum \times l \times C_{2}[/tex]
[tex]C_{2}[/tex] = [tex]\frac{0.07058}{6.17 \times 10^{3} \times 1}[/tex]
= [tex]0.01144 \times 10^{-3} mol/L[/tex]
= 0.01144 mmol/L
Thus, we can conclude that linear range of phenol concentration is 0.01144 mmol/L to 0.187 mmol/L.
