Answer these questions:

1.      At pH 9.2, seconal absorbs at 239 nm. At pH 13, the absorbance shifts to 254 nm. Of what class of compounds is this characteristic and why?

2.      Three compounds were found to have the same empirical formula, that is the same number of carbons, hydrogens, oxygens, etc.; however, compound A absorbs at 268 nm, B at 278 nm, and C at 316 nm. What might you conclude about the structures of these three compounds.

3.      The spectra of methamphetamine and diazepam are shown in the text of this module. Would you use UV spectrophotometry to screen for either or both of these compounds? Explain why.

4.      Tylenol is found to absorb at:
a)      If an acid solution in a 1 cm cuvette was found to have an absorbance of 0.669 absorbance units,
b)     what was the concentration of tylenol in the solution?
c)      If the absorbance of a basic solution of tylenol was 2.0,
d)     what would its concentration be?

5.      Why is UV/visible spectrophotometry most often used for screening rather than for confirmation ?

6.      How can the relative scarcity of drugs that fluorescence be an advantage in some instances and a disadvantage in others?