90 Thu Oct 14 10:15:08 2021 (GMT-04:00) 80- 70- 60 50- 40- 30 20 Corburgi 10- 0- -10- -20- 4000 3500 3000 2500 2000 1500 1000 500 Wavenumbers (cm-1) u Oct 14 10:23:42 2021 (GMT-04:00) D PEAKS: Spectrum: Region: Absolute threshold: 35.088 Sensitivity: Thu Oct 14 10:15:08 2021 (GMT-04:00) 4000.00 400.00 50 Daek liot: 1742.66 1242.20

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Which of the following compounds has a UV spectroscopic signal at the lowest absorption energy? II IV A. I B. II C. II D. IV

Use the Text Submission box to answer the following question. Consider the reaction shown below. For a particular concentration of sodium methoxide, the absorbance at 244 nm is measured using UV-vis spectroscopy. Over an initial period, the absorbance at 244 nm increases from 0.50 to 0.60. When the concentration of sodium methoxide is doubled, the absorbance at 244 nm measured after the same initial period is 0.70. What can you conclude about the mechanism of the reaction? NaOCH 3 Amax = 244 nm

What happens to emission intensity when KI is added to a fluorescein solution and why?

7. Explain how you could tell them apart, both by mass spectrometry and by infrared spectroscopy. IR values and MS fragmentations H 120 7

With reference to the provided IR spectra, answer the following questions.

2. For the reaction performed in this experiment, the IR spectra for the reactants and product are shown below. For the IR spectra of acetone and the product, identify the important IR signals for each spectrum. Specifically: - for the IR spectrum of acetone, identify the signal which indicates the presence of the C=O bond and the signal which represents the CH bond (indicate the hybridization of the carbon). -for the IR spectrum of the product indicate which signal represents the CH bond (hybridization?) and which signal represents the O-H bond. You may write the answers on the spectra if you wish. Reactant: 1-bromobutane % Trasm ittaice 100 % Transmittance 20 GO 40 20 0 4000 Reactant: acetone 100 DO GO 40 20 3600 4000 3500 3000 IAN 3000 2500 M wavenumber (cm) 2500 2000 n 2000 Wavenumber (cm³¹) 1500 VI 1500 1000 1000

Chapter 18 Worksheet 18-1 Properties of Light 1. The stretching frequency of a carbonyl (C=0) bond in a typical ketone is 5.15 x 1013 Hz. The vibrational energy of the molecule increases when light of this frequency is absorbed.   a) What is the wavelength of this light in nanometers? b) What is the wavelength of this light in micrometers? c) Express the frequency of this light in wavenumbers. d) What is the energy (in joules) of a single photon of light at this frequency? e) What is the energy (in kilojoules) of one mole of photons at this frequency? f) Into what region of the electromagnetic spectrum does this radiation fall?

Sample #1 has an absorbance of 0.300. Sample #2 is the same substance and has an absorbance of 0.600 using the same equipment. What is the relative concentration of the second sample? Select one: a. The concentration of sample #2 is the square root of that of #1. b. The concentration of sample #2 is that of sample #1 squared. c. The concentration of sample #2 is half that of sample #1. d. The concentration of sample #2 is twice that of sample #1.