Question 1

VSEPR theory suggests that the sulfur pentafluoride ion SF5− adopts a trigonal bipyramidal structure. Predict the coupling pattern expected for the 19F-NMR spectrum of SF5− obtained at very low temperatures.

Accepted Answer

A)   One single peak
B)   One group of resonances, appearing as a doublet
C)   One group of resonances, appearing as a sextet
D)   Two groups of resonances, one appearing as a triplet and the second as a quartetE) B) and D)
F) None of the above

Question 2

Calculate the transmittance of a solution of benzene in cyclohexane of concentration 0.020 mol dm-3 and path length 0.20 cm at a wavelength of 255 nm, if the molar absorption coefficient at this wavelength is 210 (mol dm-3)  -1 cm-1.

Accepted Answer

A)   2.32
B)   6.92
C)   0.43
D)   0.14E) C) and D)
F) A) and B)

Question 3

The 1H NMR spectrum of 1-bromopropane would have resonances (with integral intensities)  best described by:

Accepted Answer

A)   A doublet (2H) , a doublet (2H) , and a triplet (3H) 
B)   A triplet (2H) , a sextet (2H) , and a triplet (2H)  Incorrect
C)   A quartet (2H) , a triplet (3H) , and a triplet (2H)  Incorrect
D)   A singlet (7H) E) A) and C)
F) B) and D)

Question 4

Considering the energy transitions that occur in Raman spectroscopy, predict which of the following series of peaks, in order of increasing energy, best matches what is typically observed in a Raman spectrum.

Accepted Answer

A)   Three peaks of equal intensity
B)   A low intensity peak, a very high intensity peak, a very low intensity peak
C)   A very high intensity peak, a low intensity peak, a low intensity peak
D)   A very low intensity peak, a very high intensity peak, a low intensity peakE) A) and D)
F) A) and B)

Question 5

The force constant of the bond in ClO radical is 472 N m-1. Determine the frequency of vibration of the 35Cl16O isotopomer.

Accepted Answer

A)   16.1  1013 s-1
B)   2.56  1013 s-1
C)   41.1  1013 s-1
D)   1.79  1013 s-1E) C) and D)
F) All of the above

Exam 10: Molecular Spectroscopy

Considering the energy transitions that occur in Raman spectroscopy, predict which of the following series of peaks, in order of increasing energy, best matches what is typically observed in a Raman spectrum.

Correct Answer
verified

The force constant of the bond in ClO radical is 472 N m^-¹. Determine the frequency of vibration of the ³⁵Cl¹⁶O isotopomer.

Correct Answer
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Calculate the transmittance of a solution of benzene in cyclohexane of concentration 0.020 mol dm^-³ and path length 0.20 cm at a wavelength of 255 nm, if the molar absorption coefficient at this wavelength is 210 (mol dm^-³) ^-¹ cm^-¹.

Correct Answer
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VSEPR theory suggests that the sulfur pentafluoride ion SF₅⁻adopts a trigonal bipyramidal structure. Predict the coupling pattern expected for the ¹⁹F-NMR spectrum of SF₅⁻obtained at very low temperatures.

Correct Answer
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The ¹H NMR spectrum of 1-bromopropane would have resonances (with integral intensities) best described by:

Correct Answer
verified

Exam 10: Molecular Spectroscopy

Considering the energy transitions that occur in Raman spectroscopy, predict which of the following series of peaks, in order of increasing energy, best matches what is typically observed in a Raman spectrum.

Correct AnswerverifiedShow Answer

The force constant of the bond in ClO radical is 472 N m-1. Determine the frequency of vibration of the 35Cl16O isotopomer.

Correct AnswerverifiedShow Answer

Calculate the transmittance of a solution of benzene in cyclohexane of concentration 0.020 mol dm-3 and path length 0.20 cm at a wavelength of 255 nm, if the molar absorption coefficient at this wavelength is 210 (mol dm-3) -1 cm-1.

Correct AnswerverifiedShow Answer

VSEPR theory suggests that the sulfur pentafluoride ion SF5− adopts a trigonal bipyramidal structure. Predict the coupling pattern expected for the 19F-NMR spectrum of SF5− obtained at very low temperatures.

Correct AnswerverifiedShow Answer

The 1H NMR spectrum of 1-bromopropane would have resonances (with integral intensities) best described by:

Correct AnswerverifiedShow Answer

Correct Answer
verified

The force constant of the bond in ClO radical is 472 N m^-¹. Determine the frequency of vibration of the ³⁵Cl¹⁶O isotopomer.

Correct Answer
verified

Calculate the transmittance of a solution of benzene in cyclohexane of concentration 0.020 mol dm^-³ and path length 0.20 cm at a wavelength of 255 nm, if the molar absorption coefficient at this wavelength is 210 (mol dm^-³) ^-¹ cm^-¹.

Correct Answer
verified

VSEPR theory suggests that the sulfur pentafluoride ion SF₅⁻adopts a trigonal bipyramidal structure. Predict the coupling pattern expected for the ¹⁹F-NMR spectrum of SF₅⁻obtained at very low temperatures.

Correct Answer
verified

The ¹H NMR spectrum of 1-bromopropane would have resonances (with integral intensities) best described by:

Correct Answer
verified