SPECTROSCOPY FINAL EXAM QUESTIONS AND
ANSWERS #1
The standard addition method is used in analysis when:
(a) a better precision is needed.
(b) the concentration of the standards are too low.
(c) the sample has chemical interferences. - correct answer C
Why is it easier to analyze a mixture of gaseous atomic species by absorption
spectroscopy than it is to analyze a mixture of molecular species?
(a) atomic species do not have side reactions.
(b) molecular species do not absorb light.
(c) atomic spectra have simpler narrower lines that are easier to resolve than molecular
spectra. - correct answer C
Which of the following types of transition would require the lowest energy of radiation?
(a) rotational transitions.
(b) vibrational transitions.
(c) electronic transitions. - correct answer A
A liquid sample absorbs light of wavelength 250 nm. What lamp would you need to
perform a spectroscopic analysis of this sample?
(a) deuterium
(b) tungsten
(c) deuterium and tungsten - correct answer A
A liquid sample absorbs light of wavelength 510 nm. What lamp would you need to
perform a spectroscopic analysis of the sample?
(a) deuterium
(b) tungsten
(c) deuterium and tungsten - correct answer B
A molecule which has absorbed a photon of energy in the visible range could move
from the excited electronic state S1 to highly excited vibrational level of the ground state
(S0). This process is
(a) fluorescence.
(b) internal conversion.
(c) intersystem crossing. - correct answer A
Compared to the incident (exciting) radiation, fluorescent emission will have a
(a) higher energy.
(b) higher frequency.
(c) longer wavelength. - correct answer C
Which of the following is true?
ANSWERS #1
The standard addition method is used in analysis when:
(a) a better precision is needed.
(b) the concentration of the standards are too low.
(c) the sample has chemical interferences. - correct answer C
Why is it easier to analyze a mixture of gaseous atomic species by absorption
spectroscopy than it is to analyze a mixture of molecular species?
(a) atomic species do not have side reactions.
(b) molecular species do not absorb light.
(c) atomic spectra have simpler narrower lines that are easier to resolve than molecular
spectra. - correct answer C
Which of the following types of transition would require the lowest energy of radiation?
(a) rotational transitions.
(b) vibrational transitions.
(c) electronic transitions. - correct answer A
A liquid sample absorbs light of wavelength 250 nm. What lamp would you need to
perform a spectroscopic analysis of this sample?
(a) deuterium
(b) tungsten
(c) deuterium and tungsten - correct answer A
A liquid sample absorbs light of wavelength 510 nm. What lamp would you need to
perform a spectroscopic analysis of the sample?
(a) deuterium
(b) tungsten
(c) deuterium and tungsten - correct answer B
A molecule which has absorbed a photon of energy in the visible range could move
from the excited electronic state S1 to highly excited vibrational level of the ground state
(S0). This process is
(a) fluorescence.
(b) internal conversion.
(c) intersystem crossing. - correct answer A
Compared to the incident (exciting) radiation, fluorescent emission will have a
(a) higher energy.
(b) higher frequency.
(c) longer wavelength. - correct answer C
Which of the following is true?
