Analytical Chemistry Final- ACS Exam 2024
Extraction
The physical Transfer of solute from one phase to another
Partitioning
Grating
optical element with closely spaced lines
diffraction
propagation of light by a slit
The bending of light rays by a grating
polychromatic
multiple wavelengths
monochromatic
one wavelength
Which process usually occurs first after a molecule absorbs a photon?
A. phosphorescence
B. intersystem crossing
C. fluorescence
D. Vibrational relaxation
D.
A solute is to be extracted using 150 mL of solvent. Of the options below, which
will extract the maximum amount of solute?
A) extract with 30 mL five times
B) extract with 37.5 mL four times
C) extract with 75 mL twice
D) extract once with the entire volume E) extract with 50 mL three time
A
After a molecule absorbs a photon, several processes can occur. What is the
correct order (first to last) of processes that occur for molecules that fluoresce?
A) Absorbance, internal conversion, fluorescence
B) Absorbance, intersystem crossing, fluorescence
C) Absorbance, vibrational relaxation, intersystem crossing, fluorescence
D) Absorbance, vibrational relaxation, fluorescence
D
adsorption chromatography
partition chromatography
solute equilibrates between the stationary liquid and the mobile phase
ion-exchange chromatography
solute ions of the opposite charge are attracted to the stationary phase
molecular exclusion chromatography
solute is separated based on size
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
, baseline
widths, and kA and kB are the retention factors for solutes A and B.
Which of the following is a measure of kA?
A. (tA-tm)/wA
B. (tA-wA)/tm
C. tA/tm
D. tA-tm
E. (tA-tm)/tm
F. tA/wA
E.
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
baseline
widths, and kA and kB are the retention factors for solutes A and B.
Which of the following is a measure of the resolution of A and B?
A. (tB-tm)/(tA-tm)
B. (tB-tA)/wavg
C. tB-tA
D. tB/tA
E. ( tB-tA)/tm
F. (tA/wA)-(tB/wB
B.
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
baseline
widths, and kA and kB are the retention factors for solutes A and B.
How might tm be determined?
A. from stationary phase particle size
B. from average of baseline peak widths
C. from first disturbance of baseline
C.
Photocell
phototube
photodiode
commonly micro fabricated into arrays of 500 or more individual detectors
photomultiplier tube
Isocratic elution
elution with a constant composition mobile phase
gradient elution
packed column
Extraction
The physical Transfer of solute from one phase to another
Partitioning
Grating
optical element with closely spaced lines
diffraction
propagation of light by a slit
The bending of light rays by a grating
polychromatic
multiple wavelengths
monochromatic
one wavelength
Which process usually occurs first after a molecule absorbs a photon?
A. phosphorescence
B. intersystem crossing
C. fluorescence
D. Vibrational relaxation
D.
A solute is to be extracted using 150 mL of solvent. Of the options below, which
will extract the maximum amount of solute?
A) extract with 30 mL five times
B) extract with 37.5 mL four times
C) extract with 75 mL twice
D) extract once with the entire volume E) extract with 50 mL three time
A
After a molecule absorbs a photon, several processes can occur. What is the
correct order (first to last) of processes that occur for molecules that fluoresce?
A) Absorbance, internal conversion, fluorescence
B) Absorbance, intersystem crossing, fluorescence
C) Absorbance, vibrational relaxation, intersystem crossing, fluorescence
D) Absorbance, vibrational relaxation, fluorescence
D
adsorption chromatography
partition chromatography
solute equilibrates between the stationary liquid and the mobile phase
ion-exchange chromatography
solute ions of the opposite charge are attracted to the stationary phase
molecular exclusion chromatography
solute is separated based on size
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
, baseline
widths, and kA and kB are the retention factors for solutes A and B.
Which of the following is a measure of kA?
A. (tA-tm)/wA
B. (tA-wA)/tm
C. tA/tm
D. tA-tm
E. (tA-tm)/tm
F. tA/wA
E.
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
baseline
widths, and kA and kB are the retention factors for solutes A and B.
Which of the following is a measure of the resolution of A and B?
A. (tB-tm)/(tA-tm)
B. (tB-tA)/wavg
C. tB-tA
D. tB/tA
E. ( tB-tA)/tm
F. (tA/wA)-(tB/wB
B.
Consider a reversed phase chromatographic separation of solutes A and B,
where tm is
the mobile phase retention time, tA and tB are the retention times of the solutes A
and B, wA and
wB are the baseline widths of peak A and peak B, wavg is the average of the two
baseline
widths, and kA and kB are the retention factors for solutes A and B.
How might tm be determined?
A. from stationary phase particle size
B. from average of baseline peak widths
C. from first disturbance of baseline
C.
Photocell
phototube
photodiode
commonly micro fabricated into arrays of 500 or more individual detectors
photomultiplier tube
Isocratic elution
elution with a constant composition mobile phase
gradient elution
packed column
