CHEM 1E EXP 5 Spectroscopy and Beers Law Analysis_Revision_Fall18 (1)

. Atomic Absorption Spectroscopy (AAs) and Atomic Emission Spectroscopy (AEs) have many uses including in forensic science and choice of colors for fireworks. Explain in not more than six (6) sentences how this is so.

In NMR we use solvents such as tetrachloromethane to prepare samples for the machine What is the molecular formula of tetrachloromethane? ii Why do you think tetrachloromethane is used as a solvent? iii Solvents that contain deuterium, D, are also used as solvents in NMR. Deuterium is the isotope 2H. A substance in which 'H is replaced by 2H is said to be deuterated. Why would the deuterated solvent CDCI, be used instead of CHCI,? Your answer

9. Absorption spectra for molecules are more complex than atomic spectra because: C (a) Molecular species have side reactions C (b) Atomic species do not absorb light C (c) The number of energy states of molecules is enormous when compared with the number of energy states for isolated atoms. 10 absorption / emission of light by a molecule and describe the processes in terms of energy levels. How this information can be used for obtaining analytical information on an analyte of interest? Explain the phenomenon of

Write the electron configuration for atoms of chlorine Cl in their ground state and use it to predict which of the following PES spectra would be generated by these atoms. II 347 29.1 2.38 2.05 37.1 3.93 0,42 239 16.05 100 10 100 10 lonization Energy (MJ/mol) lonization Energy (MJ/mol) II IV 273 20.2 2.44 24.1 2.82 26.8 1.25 31.5 1.52 100 10 100 10 lonization Energy (MJ/mol) lonization Energy (MJ/mol) Number of Electrons Number of Electrons Number of Electrons Number of Electrons

Food dye spectroscopy  2. At what wavelengths should the readings be taken? What instrumentation will you utilize with a solution of a known dye to determine the wavelength for your analysis?

kindly answer this question A i & ii

What is signifiant about the table values and how do I use them to answer my question?

A east.cengagenow.com C OWLV2 |Online teaching and learning resource from Cengage Learning urse: CHM 103 003 General Chemistry 0:58:02 [References] Which of the following compounds contains only one unshared pair of valence electrons? NH3 1 pt 1 pt O H,0 1 pt O CH4 O NaCl 1 pt O BF3 1 pt 1 pt Try Another Version 5 item attempts remaining Submit Answer 1 pt 1 pt 1 pt 1 pt 1 at gnment Cengage Learning Cengage Technical Support

Topic:Fluorescence spectroscopy An introduction explaining: what the technique is about, the basic principles/ theory of the technique, and how the instrument or spectrometer works.

2. Molecules absorb IR radiation consistent with vibrational energy and rotational energy. Which of these is present in condensed phases (liquid, solution, solid)?

Spectroscopy relies on the excitation and relaxation of electrons. Which of the following statements about spectroscopy is true? Phosphorescence is the emission of a photon of light as an electron transitions from the excited singlet state to ground state. Collisional deactivation of an excited molecule decreases the absorbance response. Molecular absorption spectrometry measures the change in light intensity as light passes through a sample. Fluorescence is the absorption of a photon of light as an electron transitions from the ground state to an excited triplet state.

3. Bromine, Br2 Consider the fragmentation of diatomic compounds. For example, 158Br2 will give a signal at 79 for 79Br and one at 79 for Br. Br has two naturally occurring isotopes, the 79 isotope and the 81 isotope. Determine the origin (formula) of each of the signals for the mass spectrum of molecular bromine. Example, 158Br2 is equal to 79Br79Br. Relative Abundance 90 80 70 60 50 30 20 10 D 79 81 158 160 162 62 Mass (amu) Figure 4. Mass Spectrum of Br. Mass Number Measurement (cm) Abundance Formula Calculations XXXX XXXX XXXX XXXX XXXX XXXX

Assuming HCl and DC1 have the same force constant (k) or potential energy, V(x) = kx², what is the vibrational frequency of DC1 if the vibrational frequency for HCl is 3000 cm ¹? (the atomic masses for H atom, D, atom and Cl atom are 1, 2, and 35, respectively) A. 516 cm-¹ B. 1250 cm-¹ C. 2150 cm-¹ D. 3000 cm-¹ E. 4190 cm-¹

At what masses do the molecular ions occur? What are the percentages of each molecular ion?

2. a. Copper(II) acetate is a dimer, and the two copper atoms are strongly interacting. The epr spectrum consists of seven lines with intensity ratios 1:2:3:4:3:2:1. Copper nuclei have an I value of 2, and copper acetate consists of a ground state that is a singlet and an excited state that is a triplet. Explain the number and relative intensity of the lines in the spectrum. [For answer, see B. Bleaney and K. D. Bowers, Proc. Roy. Soc. (London), A214, 451 (1952).] b. What would you expect to happen to the signal intensity as a sample of copper acetate is cooled? Why?