Indicate the answer choice that best completes the statement or answers the question.
1. A(n) _____________ is used to grind solids into smaller particles.
a. orbital shaker
b. vortexer
c. mixer
d. mortar and pestle
e. centrifuge
ANSWER: d
2. Ca2+ in lake water can be measured with a reagent called EDTA. However, the presence of Al3+ will
provide a false signal because it reacts with EDTA as well. The method of adding excess F− to minimize
the effects of Al3+ on the Ca2+ determination is called
a. interference.
b. masking.
c. obscurance.
d. cloaking.
e. camouflaging.
ANSWER: b
3. For separations performed using a chromatography column, the plot of detector response versus time is
a(n) __________, and the area under the peak is _________ to the quantity of compound passing
through the detector.
a. column plot; proportional
b. column plot; inversely proportional
c. chromatogram; proportional
d. chromatogram; inversely proportional
e. absorbance spectrum; proportional
ANSWER: c
4. The liquid above the packed solid following a centrifugation is the ___________.
a. solvonatant
b. analyte
c. serum
d. decanted
e. supernatant
ANSWER: e
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5. A(n) __________ sample is a sample in which the chemical composition differs from place to place.
a. variable
b. homogeneous
c. random
d. inconsistent
e. heterogeneous
ANSWER: e
6. Sampling is the process in which
a. general questions are translated into specific questions to be answered through chemical
measurements.
b. the chemical literature is searched to find appropriate procedures or, if necessary, devise new
procedures to make the required measurements.
c. a representative material is selected to analyze.
d. a representative sample is converted into a form suitable for analysis.
e. the concentration of analyte is measured in several identical portions.
ANSWER: c
7. Which of the following analyses is NOT quantitative?
a. A home pregnancy test.
b. A chocolate bar contains 33% fat.
c. The density of water is determined to be 1.0 g/mL at 4 ºC.
d. A tap water sample was found to contain 13 200 ppb Pb2+.
e. A driver had 0.12% alcohol in his bloodstream.
ANSWER: a
8. __________ occurs when a species other than analyte increases or decreases the analytical signal and
makes it appear that the concentration is greater or less than the real concentration.
a. Interference
b. Masking
c. Aliquots
d. Disruption
e. Intervention
ANSWER: a
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9. ____________ is the series of procedures applied to a sample prior to analysis.
a. Preanalysis clean up
b. Sample preparation
c. Filler elimination
d. Matrix removal
e. Lot cleaning
ANSWER: b
10. ______________ is the process of procuring a representative sample to analyze.
a. Inspection
b. Examination
c. Representation
d. Sampling
e. Partaking
ANSWER: d
11. A researcher is searching the literature for a paper related to the zinc concentrations in the cerebrospinal
fluid of mice by inductively coupled plasma - mass spectrometry (ICP-MS). Which of the following sets
of terms is most likely to yield the most pertinent information?
a. rodent, zinc
b. rodent, zinc, cerebrospinal fluid, ICP-MS
c. rodent, zinc, bodily fluid
d. zinc, cerebrospinal fluid, ICP-MS
e. zinc, cerebrospinal fluid
ANSWER: b
12. ______________ is the substance being measured during a chemical analysis.
a. Bulk
b. Lot
c. Sample
d. Analyte
e. Aliquot
ANSWER: d
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13. When extracting a sample with a liquid, the liquid is __________ from the sample.
a. transferred
b. drained
c. decanted
d. effused
e. dispensed
ANSWER: c
14. A sample with a uniform chemical composition is a ___________ sample.
a. homologous
b. homogeneous
c. uniform
d. consistent
e. heterogeneous
ANSWER: b
15. A(n) ___________ is a plot of detector response as a function of analyte concentration. The curve is
constructed using ___________ containing known concentrations of the analyte of interest.
a. analyte curve; response solutions
b. response curve; standard solutions
c. analyte curve; analyte solutions
d. calibration curve; standard solutions
e. response curve; response solutions
ANSWER: d
16. A(n) __________ is a suspension of a solid in a liquid.
a. slurry
b. colloid
c. gel
d. supernatant
e. allotrope
ANSWER: a
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