CHEM 210 FINAL EXAM
1. In particular gravimetric analysis, the precipitate of
barium sulfate was weighed before it was completely
dried. The likely impact of this error on the calculated
result is.
A. Minimal, because the mass of water is very low.
B. Lower result than correct value.
C. Higher result than correct value.
D. Minimal, because calculation assumes a hydrated sample is
produced.
E. All of the above are not correct.
2. Atomic spectroscopy is...
A. Measurement of intensity of emitted light at a particular
wavelength from
the atoms that are excited thermally.
B. Measurement of absorbance of emitted light at particular
wavelength from
atoms excited thermally.
C. Measurement of intensity of emitted light at particular
wavelength from the
atoms that are excited by monochromatic light.
D. Measurement of intensity of absorbed light at a particular
wavelength from
,the atoms that are excited thermally.
E. None of the above.
3. In many countries, fish with more than 0.500 ppm
mercury is considered
unsafe. In one experiment, a 0.750 g piece of tuna was
appropriately treated
and made up to 10.0 mL solution. This solution returned
an absorbance of 0.70.
Using the calibration graph below, what can be concluded
from this analysis?
A. The tuna does not contain mercury.
B. The concentration of mercury in the tuna is less than 0.500
ppm and it can
be eaten safely.
C. The concentration of mercury is exactly equal to 0.500 ppm
and may or may
not be safe to eat.
D. The concentration of mercury in the tuna is greater than 0.500
ppm and it
should not be eaten.
E. None of the above.
4. Of the following compounds, which would you expect to
elute first from a
, nonpolar gas chromatographic column?
A. Methanol (CH3OH)
B. Ethanol (CH3CH2OH)
C. n-Propanol (CH3CH2CH2OH) D. n-Butanol (CH3CH2CH2CH2OH)
E. n-Pentanol (CH3CH2CH2CH2CH2OH)
5. Separation of ions in mass spectrometer take place on
the basis of which of the following?
A) Mass
B) Charge
C) Molecular weight
D) Mass to charge ratio
E) None of the above.
6. Which of the following are examples of systematic errors?
I. Weighing a precipitate on an electronic balance.
II. Consistently reading burette volumes from the top of the
meniscus.
III. Using an incorrectly labelled standard solution in a titration.
A. I, II and III
B. I and III only
C. I and II only
D. II and III only
1. In particular gravimetric analysis, the precipitate of
barium sulfate was weighed before it was completely
dried. The likely impact of this error on the calculated
result is.
A. Minimal, because the mass of water is very low.
B. Lower result than correct value.
C. Higher result than correct value.
D. Minimal, because calculation assumes a hydrated sample is
produced.
E. All of the above are not correct.
2. Atomic spectroscopy is...
A. Measurement of intensity of emitted light at a particular
wavelength from
the atoms that are excited thermally.
B. Measurement of absorbance of emitted light at particular
wavelength from
atoms excited thermally.
C. Measurement of intensity of emitted light at particular
wavelength from the
atoms that are excited by monochromatic light.
D. Measurement of intensity of absorbed light at a particular
wavelength from
,the atoms that are excited thermally.
E. None of the above.
3. In many countries, fish with more than 0.500 ppm
mercury is considered
unsafe. In one experiment, a 0.750 g piece of tuna was
appropriately treated
and made up to 10.0 mL solution. This solution returned
an absorbance of 0.70.
Using the calibration graph below, what can be concluded
from this analysis?
A. The tuna does not contain mercury.
B. The concentration of mercury in the tuna is less than 0.500
ppm and it can
be eaten safely.
C. The concentration of mercury is exactly equal to 0.500 ppm
and may or may
not be safe to eat.
D. The concentration of mercury in the tuna is greater than 0.500
ppm and it
should not be eaten.
E. None of the above.
4. Of the following compounds, which would you expect to
elute first from a
, nonpolar gas chromatographic column?
A. Methanol (CH3OH)
B. Ethanol (CH3CH2OH)
C. n-Propanol (CH3CH2CH2OH) D. n-Butanol (CH3CH2CH2CH2OH)
E. n-Pentanol (CH3CH2CH2CH2CH2OH)
5. Separation of ions in mass spectrometer take place on
the basis of which of the following?
A) Mass
B) Charge
C) Molecular weight
D) Mass to charge ratio
E) None of the above.
6. Which of the following are examples of systematic errors?
I. Weighing a precipitate on an electronic balance.
II. Consistently reading burette volumes from the top of the
meniscus.
III. Using an incorrectly labelled standard solution in a titration.
A. I, II and III
B. I and III only
C. I and II only
D. II and III only
