The molar absorptivity of a compound at 500 nm wavelength is 252 M-1cm-1. Suppose one prepares a solution by dissolving 0.00140 moles of a solute in enough water to make a 500.0 mL solution. What would be the absorbance in a 3 .00 mm pathlength cell?

Respuesta :

Answer:

The absorbance of the solution is 0.21168.

Explanation:

Given that,

Wavelength = 500 nm

Molar absorptivity = 252 M⁻¹ cm⁻¹

Number of moles = 0.00140

Volume of solution = 500.0 mL

Length = 3.00 mm

We need to calculate the molar concentration

Using formula of the molar concentration

[tex]C=\dfrac{N}{V}[/tex]

Where, N = number of moles

V = volume

Put the value into the formula

[tex]C=\dfrac{0.00140}{0.5000}[/tex]

[tex]C=0.0028\ M[/tex]

We need to calculate the absorbance of the solution

Using formula of absorbance

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

Put the value into the formula

[tex]A=252\times0.0028\times0.300[/tex]

[tex]A=0.21168[/tex]

Hence, The absorbance of the solution is 0.21168.

The absorbance of a compound, with a molar absorptivity at 500 nm wavelength of 252 M⁻¹ cm⁻¹, prepared by dissolving 0.00140 moles of a solute in enough water to make a 500.0 mL solution, measured in a 3 .00 mm pathlength cell, is 0.212.

First, we will calculate the molarity of the compound, which is equal to the moles of solute divided by the liters of solution.

[tex]M = \frac{0.00140mol}{0.5000L} = 0.00280 M[/tex]

Then, we will convert 3.00 mm to cm using the conversion factor 1 cm = 10 mm.

[tex]3.00 mm \times \frac{1cm}{10mm} = 0.300 cm[/tex]

Finally, we will calculate the absorbance of the compound using the Beer–Lambert equation.

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

where,

  • A: absorbance
  • ε: molar absorptivity
  • b: length of light path
  • C: molar concentration

[tex]A = \epsilon \times b \times C = \frac{252}{M.cm} \times 0.300 cm \times 0.00280 M = 0.212[/tex]

The absorbance of a compound, with a molar absorptivity at 500 nm wavelength of 252 M⁻¹ cm⁻¹, prepared by dissolving 0.00140 moles of a solute in enough water to make a 500.0 mL solution, measured in a 3 .00 mm pathlength cell, is 0.212.

You can learn more about the Beer–Lambert law here: https://brainly.com/question/24571070?referrer=searchResults

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