Which of the following molecules has the strongest absorbance of UV light? water O heptane benzene Ethanol Question 2 1 pts Reaction of FeCl2 with 1, 10-phenanthroline gives a red-colored complex that has a maximum absorbance at 510 nm. What is the best way of determining the Fe2+ concentration of a water sample without any dilution of the sample? Use an Atomic Absorption Spectrometer Use a Fluorescence Spectrometer O Use an Atomic Emission Spectrometer Use a UV-vis spectrophotometer that has a Variable Path Length Slope System Question 3 1 pts In a fluorescence spectrometry, the relationship between fluorescence intensity (F) and the concentration of an analyte (c) is: F=10(1-e-abc)o, where the absorptivity of the analyte (a), light pathlength (b), the intensity of the incident radiation (lo) and the quantum efficiency (0) are constant for a specific analyte and a sample holder. What is required for quantitative determination of the analyte concentration with a fluorescence spectrometer? O Alaser with low intensity must be used so that the chemical structure of the analyte will not be destructed The concentration of the analyst in the sample and the standard must be very low Standards with a wide range of analyte concentrations must be used so that a full curve of F vs. c can be plotted. The light source must have a wide range of wavelengths