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After creating a Beer's Law plot using standard solutions of Q, you determined the slope of Beer's Law to be 0.543 M-1. Your unknown solution of Q tested in Part B of the experiment had an absorbance of 0.144. Determine the concentration (in molarity) of the unknown solution Q from Part B. Do not use scientific notation or units in your response. If Carmen adds zeros after the decimal place, your answer will still be graded correctly.

Respuesta :

Answer : The concentration (in molarity) of the unknown solution Q is, 0.265

Explanation :

Using Beer-Lambert's law :

[tex]A=\epsilon \times C\times l[/tex]

where,

A = absorbance of solution

C = concentration of solution

l = path length

[tex]\epsilon[/tex] = molar absorptivity coefficient

From the Beer's Law plot between absorbance and concentration we concldue that the slope is equal to [tex]\epsilon \times l[/tex]  and path length is 1 cm.

As we are given that:

Slope = 0.543 M⁻¹

and,

Slope = [tex]\epsilon \times l[/tex]

[tex]\epsilon \times l=0.543M^{-1}[/tex]

[tex]\epsilon \times 1cm=0.543M^{-1}[/tex]

[tex]\epsilon=0.543M^{-1}cm^{-1}[/tex]

Now we have to determine the concentration (in molarity) of the unknown solution Q.

Using Beer-Lambert's law :

[tex]A=\epsilon \times C\times l[/tex]

[tex]0.144=0.543M^{-1}cm^{-1}\times C\times 1cm[/tex]

[tex]C=0.265M[/tex]

Therefore, the concentration (in molarity) of the unknown solution Q is, 0.265

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