[zzanarchyzz]

I have to do a lab finding out the rate equation of a specific reaction. I cant tell you the reaction because that would be considered cheating (essentially plagiarism). But I have a very specific question that I cant seem to find online about the Beer-Lambert law.

I am using absorbance to calculate concentration using the Beer-Lambert law, however, because there are multiple products to this reaction which are all diluted in water, Im not sure what coefficient of molar absorptivity to use. Do I have to use the molar absorptivity of the ENTIRE solution (all the products together) or just the product which is causing the color of the solution (in this case, just solid sulfur).
Thanks in advance, I really needed the help.

[kriggy]

You use only the product which makes the color of the solution. You compensate the absorbance of the rest by using appropriate blanc sample.

[Borek]

Absorbance of the solution is a sum of absorbances of individual solution components. If you can find wavelength for which only one of them absorbs, you can find the concentration of this one compound. Otherwise you may have to use some other information (like ratio calculated from the stoichiometry) to find out individual concentrations. Hard to tell not knowing the system.

What I don't like about your description is the idea of using spectrophotometry for a suspension. Beer-Lambert law works for homogeneous mixtures, for suspension you should use related techniques - turbidimetry or nephelometry.