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Unformatted text preview: d at the wavelength of the Red absorption maximum.
According to the modified form of Beer's Law introduced above, one can determine the
numerical value of * ( = ℓ ) for some solute at a given wavelength by determining the
slope of a plot of absorbance vs. concentration. 62 You may find it useful to use a spreadsheet program to do the following calculations.
1. Calculate the molar concentrations of the eight solutions you studied.
2. Calculate the 16 absorbances and use them along with the concentrations calculated in
Step 1 to prepare four graphs of absorbance vs. concentration. Each of your plots
should occupy most of an 8.5"x11" sheet of graph paper. From these plots determine
the four pertinent values of *. (You must plot the data even if you have a hand
calculator that will do linear regression for you. Many scientists have been blindsided
by doing computer fits to data that really did not obey the fitting equation. If your
plots are nicely linear then you can certainly get t...
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- Spring '07