Question

How will you use a solution of known concentration of one of the food dyes to determine the relationship between concentration and absorbance? Be sure to explain how you determined the wavelength for your analysis.

What method will you use to assess the absorbance-concentration relationship? (The most obvious method is to see if there is a linear relationship between the absorbance and the concentration. What methods do you know that might reveal such a linear relationship?)​

Answer 1

When a beam of mono chromatic radiation is passed through a solution,it is absorbed by the solution and hence the intensity of exiting radiation is reduced.usig a spectrometer the intensity of entering and exiting light is measured.Different materials absorb different wavelengths of light.

It is possible to relate the absorbance at a given wavelength to the concentration of the given absorbing material in the solution.

The relationship between absorbance and concentration of a solution is known as Beer-Lamberts law.using the law we can calculate the absorbance

A=lc

A=absorption of the solution.

=molar absorptivity

l=cell path length

c=concentration of the absorbing species

By plotting absorbance against concentration we get a linear relationship .

The wavelength is measured using spectrometer.