TEST BANK Flashcards
Sampling type that eliminates questions of bias in selection
a. composite c. systematic
b. stratified d. random
d. random
When aqueous and nonaqueous liquids are combined, they usually form an immiscible mixture,
such as oil and water. A ________ helps in separating the liquids into two samples.
a. pipet c. separatory funnel
b. beaker d. rotary evaporator
c. separatory funnel
Pre-treatment of solid samples prior analysis.
a. Leaching and extraction of soluble components
b. Filtering of mixtures of solids, liquids and gases to leave particulate (solid) matter
c. Grinding
d. All of the above
d. All of the above
Mixtures of liquids and solids are usually separated prior analysis by
a. filtering
b.decanting
c. centrifuging
d. All of the above
d. All of the above
In the decomposition and dissolution of solids during sample preparation, which of the following is
expensive and often the last resort?
a. Acid treatment using oxidation c. Dissolution using ultrasound&appropriate solvent
b. Fusion technique d. Simple dissolution
b. Fusion technique
Reliability of the results decreases with a decrease in the level or concentration of the:
a. matrix c. reactant
b. analyte d. product
b. analyte
Properties of nitric acid making it the preferred acid for digesting samples for the analysis of
metals
a. acts as a strong acid
b. as an oxidizing agent
c. does not form insoluble compounds with metals/nonmetals
d. All of the above
d. All of the above
Primary sample preparation method for organics
a. Sonication
b. Acid-digestion
c. Extraction
d. All of the above
c. Extraction
Possible sources of contamination during sample preparation include:
a. Reagents (tracers)
b. Glassware/equipment
c. Cross-contamination between high- and low-activity samples
d. All of the above
d. All of the above
. Containers that should not be used for dry ashing because the elevated temperatures
exceed the melting point of these materials
a. zirconium
b. platinum
c. Glass and plastic
d. porcelain
c. Glass and plastic
The size of the sample taken for analysis depends on the concentration of the
a. analyte
b. equipment to be used
c. specific tests
d. All of the above
d. All of the above
Equipment commonly used to homogenize the contents of an open beaker.
a. Magnetic stirrer
b V-blenders
c. Ball and rod mills
d. tube rotator
a. Magnetic stirrer
The maximum holding time for acid preserved samples that will be subjected to determination of
metals is
a. 3 months c. 6 months
b. 1 week d. 48 hours
c. 6 months
A fraction of the sample actually used in the final laboratory analysis.
a. composite sample c. laboratory sample
b. sub-sample d. a, b and c
c. laboratory sample
A change in the analytical signal caused by anything in the sample other than analyte.
a. matrix effect c. absorbance
b. interference d. transmittance
a. matrix effect
Medium containing analyte.
a. reactant
b. matrix
c. solute
d. reference material
b. matrix
The total error of an analytical result is the sum of
a. sampling
b. sample preparation
c. analytical errors
d. All of the above
d. All of the above
The holding time for samples for metal determination preserved using nitric acid, 4 mL of dilute
3:1 is
a. 28 days c. 3 days
b. 2 weeks d. 1 year
a. 28 days
When samples cannot be dried because they decompose at the temperatures necessary to drive off the
water, the samples can be analyzed as
a. wet basis
b. dry basis
c. received basis
d. All of the above
d. All of the above
Organic components in solid samples are extracted from the matrix by continuously washing
the solid with a volatile solvent in a specialized piece of glassware
a. Soxhlet extraction
b. Ultrasonic extraction
c. Filtration
d. Rotary evaporation
a. Soxhlet extraction
In liquid-liquid extraction, it is often necessary to determine which liquid is aqueous and which
liquid is nonaqueous. To test the liquids, add a drop of water to the top layer. If the drop
dissolves
in the top layer, the top layer is
a. nonaqueous
b. aqueous
c. miscible
d. denser
b. aqueous
. It is important to discard containers that are scratched or abraded on their interior surfaces. The
internal surface area of a container, whether used for sample preparation or storage, may cause
loss of
a. matrix
b. analyte
c. weight
d. ash
b. analyte
Process by which a sample population is reduced in size to an amount of homogeneous material
that can be conveniently handled in the lab in which the composition is representative of the
population.
a. selection
b monitoring
c. sampling
d. segregation
c. sampling
As a general rule, the error in sampling and the sample preparation portion of an analytical
procedure is considerably higher than that in the
a. methodology
b treatment
c. preservation
d. subsampling
a. methodology
Locating the adulterated portion of the lot for sampling is an example of
a. random sampling
b. selective sampling
c. composite sampling
d. stratified sampling
b. selective sampling
Homogenization during sample preparation can be achieved using ___
a. mechanical devices (mixers, blenders, etc.)
b enzymatic methods
c. chemical methods
d. All of the above
d. All of the above
Glass container is not suitable for
a. inorganic trace analyses
b. oil and grease determination
c. microbiological analyses
d. all of the above
a. inorganic trace analyses
To increase/decrease analyte concentration, pre-concentration is needed for almost all trace
analysis, ________ is used for the analysis of highly contaminated samples so the
concentration
falls within the calibration range.
a. centrifugation
b. separation
c. dilution
d. none of the above
c. dilution
Chemical derivatization is used to increase or decrease volatility for _________ analysis
a. AAS
b. GC and HPLC
c. PCR
d. none of the above
b. GC and HPLC
Acid digestion via hot-plate digestion or microwave-assisted is one way of sample preparation
in the analysis of
a. Total metal
b. Bioactive compounds
c. Alcohols
d. Sugars
a. Total metal
GFAA (Graphite Furnace Atomic Absorption) do not use HCl since Cl- interferes. Diluted
______ acid is used.
a. Phosphoric Acid
b. Acetic acid
c. Nitric Acid
d. Sulfuric Acid
c. Nitric Acid
Partitioning of analytes between water phase and organic phase
a. Liquid-liquid extraction
b. Soli phase extraction
c. Ultrasonic extraction
d. Pressured Fluid Extraction (PFE)
a. Liquid-liquid extraction
The amounts of all constituents in the samples were determined
a. Complete (or ultimate) analysis
b. Partial analysis
c. Elemental analysis
d. All of the above
a. Complete (or ultimate) analysis
Implies that the constituent determined was present in high concentration
a. Trace analysis
b. Macro analysis
c. Elemental analysis
d. All of the above
b. Macro analysis
Quantitative chemical analysis of weighing a sample, usually of a separated and dried precipitate.
a. Titrimetric analysis
b. Volumetric analysis
c. Gravimetric analysis
d. Elemental analysis
c. Gravimetric analysis
A chemical grade of highest purity and meets or exceeds purity standards set by American
Chemical Society
a. Technical grade
b. Laboratory grade
c. Pure or practical grade
d. ACS grade
d. ACS grade
Which of the following is a primary standard for use in standardizing bases?
a. Ammonium hydroxide
b. Sulfuric acid
c. Acetic acid
d. Potassium hydrogen phthalate
d. Potassium hydrogen phthalate
How would you prepare 500.0 mL of 0.2500 M NaOH solution starting from a concentration of
1.000 M?
a. Transfer 125 mL from initial solution (1.000 M) and complete with solvent to 500.0
mL.
b. Transfer 121 mL from initial solution (1.000 M) and complete with solvent to 500.0
mL.
c. Transfer 122 mL from initial solution (1.000 M) and complete with solvent to 500.0
mL.
d. Transfer 112 mL from initial solution (1.000 M) and complete with solvent to 500.0
mL.
a. Transfer 125 mL from initial solution (1.000 M) and complete with solvent to 500.0
mL.
A student performs five titrations and obtains a mean result of 0.110 M, with a standard
deviation of 0.001 M. If the actual concentration of the titrated solution is 0.100 M, which of the
following is true about the titration results?
a. Accurate but not precise
b. Precise but not accurate
c. Both accurate and precise
d. Neither accurate nor precise
b. Precise but not accurate
How many grams of Sodium Persulfate (Na2S2O8) required to prepare a 1 L solution of Sodium
Persulfate with concentration of 10% (w/v). This solution is widely used as oxidizing reagent for
Total Organic Carbon analyzer (TOC).
a. 100 g of Sodium Persulfate
b. 101 g of Sodium Persulfate
c. 102 g of Sodium Persulfate
d. 99 g of Sodium Persulfate
a. 100 g of Sodium Persulfate
A solution has been prepared by transfer 60 mL from Ortho-phosphoric acid 85 % (v/v) H3PO4
and dilute to 1.0 L, what is the concentration of the new solution.
a. 10.10%
b. 9.25%
c. 12.2%
d. 5.10%
d. 5.10%
Bidirectional harpoons or double arrows (⇆) should be used to indicate ________ reactions
a. one sided
b. resonance
c. dynamic
d. reversible
d. reversible
Naphthalene (C10H8) is one of aromatic hydrocarbons measured by GC-MS. If molecular weight of
naphthalene is 128.6 g/mol; how many milligrams are required to prepare 100 mL of 2,000 ppb stock
standard solution of naphthalene from powder Naphthalene (purity of 91.5 % w/w)?
a. 2.18
b. 2.1858
c. 2.186
d. 2.1859
b. 2.1858
The number of formula mass of any solute dissolved in 1 liter of solution
a. formality
b. normality
c. molality
d. molarity
a. formality
Used to measure volumes approximately, typically with errors of several percent except for one.
a. Beakers
b. pipettes
c. reagent bottles
d. graduated cylinders
d. graduated cylinders
If the theoretical yield for a reaction was 156 grams and I actually made 122 grams of the
product, what is my percent yield?
a. 78.2%
b. 128%
c. 19.0%
d. none of these
a. 78.2%
The method of standardization can be used if a _______________ reacts quantitatively with the
reagent needed in the standard solution.
a. primary standard
b. secondary standard
c. working standards
d. intermediate solution
a. primary standard
You have a stock solution of 15.8 M HNO3. How many mL of this solution should you dilute
using only a graduated pipette to make 100.0 mL of .250 M HNO3?
a. 1.58
b. 1.582
c. 1.50
d. 1.583
a. 1.58
When making a solution from a solid reagent, if necessary, dry the solid reagent on a clean, oven
dried, watch glass at 105 ºC for 2 hours and cool it in a desiccator.
a. 121 ºC
b. 105 ºC
c. 80 ºC
d. 118 ºC
b. 105 ºC
HCl cannot be considered to be a primary standard because of its gaseous form at room
temperature, but its solutions may be standardized against anhydrous ______.
a. NaSO4
b. NaHCO3
c. Na2CO3
d. All of the above
c. Na2CO3
Requirements of a primary standards.
a. High Purity, 99.9% or better
b. Stability in air
c. Absence of hydrate water
d. All of the above
d. All of the above
Blank samples are prepared so that you have a measure of the amount that needs always to be
added to or subtracted from the end point to achieve the ________point.
a. titration error
b. equivalence
c. accuracy
d. precision
b. equivalence
Property which depends on the number of particles dissolved in a given mass of solvent.
a. vapor pressure lowering
b. boiling point elevation
c. freezing point depression
d. all of the above
d. all of the above
Boiling occur if the vapor pressure of the liquid is less than the atmospheric pressure.
a. True
b. False
c. not all the time
d. Always
b. False
What is the relationship between the temperature and the solubility of a solid in a liquid?
a. directly proportional
b. inversely proportional
c. no relationship
d. geometric
a. directly proportional
What is boiling point elevation?
a. it is the difference between the boiling points of a pure solvent and a solution
b. it is the sum of the boiling points of a pure solvent and a solution
c. it is the difference between the boiling points of a pure solute and a pure solvent
d. it is the boiling point of a solution
a. it is the difference between the boiling points of a pure solvent and a solution
A membrane that allows the passage of solvent molecules through but not solute molecules is
called
a. animal membrane
b. semipermeable membrane
c. permeable membrane
d. plant membrane
b. semipermeable membrane
The excess pressure required to stop the flow and keep the solution in equilibrium with the pure
solvent is
a. partial pressure
b. vapor pressure
c. osmotic pressure
d. atmospheric pressure
c. osmotic pressure
The separation of a mixture of substances into pure components on the basis of their differing
solubilities is
a. fractional distillation
b. vacuum crystallization
c. vacuum distillation
d. fractional crystallization
d. fractional crystallization
Which has a lower freezing point?
a. water
b. NaCl
c. NaCl solution
d. all of the above
c. NaCl solution
The reactant which is present in the smallest stoichiometric amount and which limits the amount
of product that can be formed in a reaction is
a. the limiting reagent
b. the reagent with the least number of grams
c. the excess reagent
d. the reagent with the most number of grams
a. the limiting reagent
Which of the following hastens the rate of solution?
a. pulverization
b. scratching the sides of the container
c. seeding
d. cooling
a. pulverization
A polar solute usually dissolves in a polar solvent and a nonpolar solute usually
dissolves in a nonpolar solvent. This is
a. the solubility rule
b. the “like dissolves like” rule
c. Henry’s law
d. Hund’s rule
b. the “like dissolves like” rule
A solution is _______ if more solute can dissolve in it.
a. saturated
b. supersaturated
c. unsaturated
d. concentrated
c. unsaturated
The maximum amount of solute that will dissolve in a definite amount of solvent to produce a
stable system at a specified temperature is called
a. dilution
b. solubility
c. saturation
d. concentration
b. solubility
The normality of a solution is always _______ the molarity.
a. greater than or equal to
b. greater than
c. less than or equal to
d. less than
a. greater than or equal to
Which of the following concentration units is independent of temperature?
a. molarity
b. normality
c. molality
d. percent volume
c. molality
Which is not a volumetric glassware?
a. beaker
b. burette
c. pipette
d. volumetric flask
a. beaker
Ambient laboratory conditions are not the same to standard conditions, therefore the volumes dispensed in volumetric glassware are often not the same as the manufacturer’s specifications, but within some acceptable limits determined by the manufacturer. This slight variation in volume will cause a _________ error that are based on volume-volume or mass-volume concentrations.
a. random
b. systematic
c. gross
d. all of the above
b. systematic
Glass cuvettes are typically for use in the wavelength range of visible light, whereas fused quartz tends to be used for ____________ applications.
a. microwave
b. IR
c. UV / visible
d. none of the above
c. UV / visible
In this column type, the retention is governed by the interaction of the polar parts of the stationary
phase and solute.
a. reverse phase
b. ion exchange
c. column guard
d. normal phase
d. normal phase
A stable light source in AAS analysis, which is necessary to emit the sharp characteristic spectrum
of the element to be determined
a. Tungsten lamp
b. hollow cathode lamp
c. deuterium lamp
d. Nerst blower
b. hollow cathode lamp
The HPLC column type in which molecules are separated according to size.
a. Ion exchange
b. size exclusion
c. normal phase
d. reverse phase
b. size exclusion
Non Polar Reverse phase and C8 (octyl bonded silica) are commonly used for hydrophobic
Analytes in solid phase extraction. An example is
a. C18 (octadecyl bonded silica)
b. Resins
c. Florisil
d. alumina
a. C18 (octadecyl bonded silica)
Filters that can be heated and used in gravimetric analysis.
a. ordinary filter paper
b. GFF
c. Sintered glass fibers
d. none of the above
b. GFF
Google: Sintered glass fiber
Sintered glass fibers are made by fusing glass fibers together at high temperatures. This creates a filter that is highly resistant to heat and chemicals. It can withstand temperatures up to 1200°C, making it ideal for gravimetric analysis where the precipitate needs to be dried or ignited.
Objects cannot be weighed when hot or warm. But if you were to take a sample out and wait for
it to cool it would pick up moisture like that so put it in ________.
a. an oven
b. a dessicator
c. at room temperature
d. fumehood
b. a dessicator
Weighing to constant weight means a weighing difference of _____ mg using a calibrated
analytical balance.
a. ±1.0 mg
b. ±0.01g
c. ±0.01mg
d. ±0.1mg
d. ±0.1mg
The following are common desiccants except for _______
a. Calcium Sulfate
b. Ammonium Acetate
c. Calcium Chloride
d. Magnesium Oxide
b. Ammonium Acetate
During ignition for ashing, muffle furnaces that go up to 1100oC are used primarily for this and
________ is needed to contain the sample.
a. porcelain crucible
b. evaporating dish
c. beaker
d. all of the above
a. porcelain crucible
In making standard solutions, ______ are used for measuring liquid with high accuracy.
a. beakers
b. volumetric flasks
c. Erlenmeyer flasks
d. Nesslers Tubes
b. volumetric flasks
Used for distillation or heating of liquids, allows uniform heating.
a. round bottom flask
b. Erlenmeyer flask
c. test tube
d. Florence flask
a. round bottom flask
Most popular burettes are 10 mL, 25 mL and 50 mL types. Which has the highest resolution?
a. 25 mL
b. 10 mL
c. 50 mL
d. All of the above
c. 50 mL
Used for vacuum filtration using filter paper.
a. gooch crucible
b. Buchner funnel
c. rotary evaporator
d. rubber aspirator
b. Buchner funnel
In chromatography, ________ is carried out on glass plates or strips of plastic or metal coated
on one side with a thin layer of adsorbent.
a. HPLC
b. GC
c. Paper Chromatography
d. Thin Layer Chromatography
d. Thin Layer Chromatography
The nominal volume of water (or mercury) contained, or delivered by an article of volumetric
glassware, at its reference temperature.
a. capacity
b. liter
c. mL
d. uL
a. capacity
In verification of laboratory glassware, ________ is usually measured in terms of the tolerance,
which is the uncertainty in a measurement made with the glassware. Class A volumetric
glassware has a lower tolerance than Class B.
a. mean
b. accuracy
c. difference
d. precision
b. accuracy
Glass apparatus that are generally received with calibration certificates from suppliers.
a. Class B
b. Class A
c. Erlenmeyer flasks
d. Beakers
b. Class A
All proteins absorb electromagnetic radiation of wavelength around 190 nm, which corresponds
to a excitation in the protein molecule. In which region of the spectrum is this wavelength found?
a. X-ray
b. ultraviolet
c. Visible
d. Infrared
b. ultraviolet
Chromatography is used to
a. Separate two or more compounds based on their polarities.
b. Separate two or more compounds based on their masses.
c. Separate two or more compounds based on how strongly they interact with other
compounds.
d) all of the above.
d) all of the above.
A food scientist has a sample of a plantoil and wants to determine if the oil contains saturated or
unsaturated fatty acids. Which of the following spectroscopic techniques would be most
useful for this purpose?
a.ultraviolet spectroscopy
b.visible spectroscopy
c.infrared spectroscopy
d.mass spectroscopy
c.infrared spectroscopy
A graphical representation of measuring signal as a function of quantity of analyte.
a. Calibration curve
b. Quality Control Chart
c. Absorbance Chart
d. None of the above
a. Calibration curve
The concentration at which the calibration curve departs from linearity by a specified amount
a. Limit of Blank
b. Dynamic Range
c. Limit of Linearity
d. Limit of quantitation
c. Limit of Linearity
What is the path of light through a spectrophotometer?
a. meter, photodetector, filter, sample, light source
b. meter, filter sample, photodetector, light source
c. light source, filter, sample, photodetector, meter
d. light source, sample, filter, photodetector, meter
c. light source, filter, sample, photodetector, meter
With a “standard” sample with a known absorbance and concentration and a measured absorbance, it is
easy to determine an unknown concentration of †the same substance by.
a. Beer’s Law
b. Beer and Lambert’s Law
c. Law of mass conservation
d. none of the above
a. Beer’s Law
Motion of the mobile phase through the stationary phase.
a. Elution
b. Retention time
c. Eluent
d. Elution time
a. Elution
The highest apparent analyte concentration expected to be found when replicates of a blank sample
containing no analyte are tested..
a. Limit of Detection
b. Limit of Blank
c. Limit of Linearity
d. Limit of Quantitation
b. Limit of Blank
In spectrophotometric methods, the _________ isolates the specific spectrum line emitted by
the light source through spectral dispersion.
a. monochromator
b. prism
c. sample compartment
d. detector
a. monochromator
A phase which sample is dissolved in may be gas, liquid, or supercritical fluid
a. stationary phase
b. reverse phase
c. normal phase
d. mobile phase
d. mobile phase
In AAS method, If the sample concentration is too high to permit accurate analysis in linearity
response range, there are alternatives that may help bring the absorbance into the optimum
working range.
a. sample dilution
b. using an alternative wavelength having a lower absorptivity
c. reducing the path length by rotating the burner hand
d. All of the above
d. All of the above
A technique for separating mixtures into their components in order to analyze, identify, purify, and/or
quantify the mixture or components.
a. Spectrocopy
b. Chromatography
c. Gravimetry
d. Titrimetry
b. Chromatography
A “modified” stationary phase where polar solutes run fast
a. Normal phase
b. Reverse phase
c. mobile phase
d. none of the above
b. Reverse phase
A graph showing the detectors response as a function of elution time : band’s shapes, position,
resolution
a. monitor display
b. quality control chart
c. calibration curve
d. chromatogram
d. chromatogram
The pH meter glass probe has two electrodes, one is a glass sensor electrode and the
other is a _______electrode.
a. reference
b. anode
c. cathode
d. none of the above
a. reference
Conductivity could be determined using the distance between the electrodes and their surface area
using Ohm’s law but, for accuracy, a calibration is employed using ____of well-known conductivity.
a. acid solution
b. basic solution
c. electrolytes
d. buffer solution
c. electrolytes
The electrical conductivity of water is directly related to the concentration of dissolved ionized
solids in the water or
a. Total Suspended Solids
b. Total Dissolved Solids
c. Volatile Solids
d. Total Solids
b. Total Dissolved Solids
At 510 nm, the iron orthophenanthroline complex has a molar absorptivity of 1.2 x 104. What is the concentration of iron (in ppm) in a solution which gives an absorbance of 0.002 in a
1.00-cm path length cell?
a. 7.3 x 10-3 ppm
b.8.3 x 10-3 ppm
c. 9.3 x 10-3 ppm
d.6.3x 10-3 ppm
c. 9.3 x 10-3 ppm
A=elc
e = 1/M-cm (molar absorptivity)
l = cm (path length)
c = M (concentration)
A= unitless (absorbance)
The light source used in the visible range to 340-1000 nm.
a.deuterium
b. nerst blower
c. tungsten
d.incandescent
c. tungsten
The % T of a solution in a 2.00 cm cell is 50. Calculate the %T of this solution in a 1.0 cm cell
path length.
a. 71
b. 19
c. 27
d. 20
a. 71
An air sampling canister was evacuated by the local fire dep’t and brought to the environmental lab
for analysis. It was said that the sample was taken very near the site where a rusty 55-gal drum was found
by some children. A reported unpleasant smell near the site was reported. Results of gravimetric analysis
of the gas in the canister: C – 40%, H- 6.7% , O – 53.33%. What is the liquid in the drum?
a. CH2O
b. CH3OH
c. CH3CH2O
d. none of the above
a. CH2O
A student has to measure out 9.40 mL of a liquid and selects a 100 mL graduated cylinder. To
improve the accuracy of the measurement, it would be most
effective to:
a. take the average of multiple measurements using the graduated cylinder.
b. measure the liquid using a 25 mL graduated cylinder instead.
c. estimate the measurement obtained from the graduated cylinder to an additional
significant figure.
d. measure the liquid using a 10 mL graduated pipette instead.
d. measure the liquid using a 10 mL graduated pipette instead.
Under the Bronsted concept of acids and bases, a base is
A. a proton donor
B. a proton acceptor
C. a hydroxide donor
D. an electron pair donor
B. a proton acceptor
Under the Lewis concept of acids and bases, an acid is
A. a proton donor
B. a proton acceptor
C. An electron pair donor
D. an electron pair acceptor
D. an electron pair acceptor
Under the Bronsted concept of acids and bases, an acid is
A. a proton donor
B. a proton acceptor
C. an electron pair donor
D. an electron pair acceptor
A. a proton donor
Which of the following is NOT an acid-base conjugate pair?
A. HCN and CN−
B. H2O and OH−
C. H2S and OH−
D. NH3 and NH4+
C. H2S and OH−
Predict the products of the following acid-base reaction:HCl(aq) + NaOH(aq) →
A. H3O+(aq) + OH−
B. Na+(aq) + Cl−(aq)
C. NaCl(aq) + H2O(l)
D. no reaction takes place
C. NaCl(aq) + H2O(l)
What effect will addition of sodium acetate have on the pH of a solution of acetic acid?
A. increase the pH
B. decrease the pH
C. no effect
D. cannot tell from information given
A. increase the pH
What effect will addition of excess of HCl have on the pH of a solution of NH3?
A. increase the pH
B. decrease the pH
C. no effect
D. cannot tell from information given
B. decrease the pH
A solution that causes only a relatively small change in pH upon addition of small amounts of acids and bases is
A. saturated
B. a salt
C. a buffer
D. unsaturated
C. a buffer
Which of the following is buffer?
A. NaCl/NH4Cl
B. NH3/NH4Cl
C. NH3/CH3COOH
D. CH3COOH/NaOH
B. NH3/NH4Cl
A buffer solution may be a mixture of
A. a weak acid and its salt
B. a weak base and its salt
C. an excess of a weak acid with a strong base
D. all of the above
D. all of the above
The conjugate base of acetic acid is
A. HCOOH
B. NH3
C. CH3COO−
D. OH−
C. CH3COO−
The conjugate acid of ammonia is
A. H3O+
B. NH4+
C. HCOOH
D. OH−
B. NH4+
Effect produced by an ion, say from a salt, which is the same ion produced by the dissociation of a weak acid or
base is called
A. colloidal effect
B. precipitation effect
C. common ion effect
D. ligand effect
C. common ion effect
A principle stating that if stress is applied to a system at equilibrium, the equilibrium is shifted in the
direction that tends to reduce the stress.
A. Heisenberg Uncertainty Principle
B. Le Chatelier’s Principle
C. Hund’s Rule
D. Debye-Huckel Principle
B. Le Chatelier’s Principle
Water cannot function as which one of the following?
A. a Bronsted acid
B. a Bronsted base
C. a Lewis acid
D. a Lewis base
C. a Lewis acid
HCOOK is a/an
A. acid
B. base
C. salt
D. oxide
C. salt
When a strong acid is titrated with a weak base, the pH at the equivalence point is
A. basic
B. acidic
C. neutral
D. none of the above
B. acidic
When a strong acid is titrated with a strong base, the pH at the equivalence point is
A. basic
B. acidic
C. neutral
D. none of the above
C. neutral
When NH4Cl hydrolyzes, the resulting solution is
A. acidic
B. basic
C. neutral
D. none of the above
A. acidic
Acids and Bases Which statement is true?
a. The value of the equilibrium constant increases with the addition of a catalyst
b. A catalyst speeds up both the forward and reverse reaction rates
c. The greater the activation energy, the faster the rate of reaction.
d. A catalyst increases the rate of reaction by decreasing the number of collisions
b. A catalyst speeds up both the forward and reverse reaction rates
The lining of the stomach contains cells that secrete a solution of HCl. Which drink would best
alleviate heartburn (excess acid in the stomach)?
a. milk, pH = 6.5
b. wine, pH = 3.8
c. diet soda, pH = 4.3
d. milk of magnesia, pH = 10.5
d. milk of magnesia, pH = 10.5
Which equation correctly describes the relationship between Kb and Ka for a conjugate acid/base pair?
a. Kb = Kw Ka
b. Kb = Ka / Kw
c. Kb = Kw / Ka
d. Kb = Ka + Kw
c. Kb = Kw / Ka
The following are observed characteristics of gases except for
a. gases can be compressed by application of pressure
b. gases diffuse and spontaneously mix with each other
c. pressure exerted by a gas decreases with increase in temperature
d. there is negligible attraction between particles of an ideal gas
c. pressure exerted by a gas decreases with increase in temperature
As altitude increases, air becomes less dense and
a. pressure increases
b. pressure decreases
c. pressure remains the same
d. none of the above
b. pressure decreases
Raising the temperature of an enclosed gas
a. slows down the kinetic energy of the gas molecules
b. decreases the momentum of the gas molecules
c. forces the gas particles to collide with the walls harder
d. decreases the volume of the gas
c. forces the gas particles to collide with the walls harder
At constant temperature and pressure, the rate of diffusion of a gas varies
a. inversely as its density
b. directly as its molecular mass
c. directly as the square root of its density
d. inversely as the square of its molecular mass
d. inversely as the square of its molecular mass
If the temperature of a confined gas is doubled, while the volume is held constant, what will happen to
the pressure?
a. it will be doubled
b. it will be half as large
c. it will be four times as large
d. cannot be determined
a. it will be doubled
Water boils at a lower temperature such as on top of a mountain than at sea level. This illustrates
a. Boyle’s law
b. Charles’ law
c. Graham’s law
d. Avogadro’s law
b. Charles’ law
Molecular oxygen is highly soluble in the blood because
a. the hemoglobin molecule can bind up to four oxygen molecules
b. the solubility of oxygen is increased by the higher temperature of the body
c. pressure is increased inside the body
d. pressure inside the body is different outside of it
a. the hemoglobin molecule can bind up to four oxygen molecules
What happens to the volume of a fully inflated balloon when it is taken outside on a cold day?
a. its volume decreases
b. it remains the same
c. its volume increases
d. its volume becomes equal to zero
a. its volume decreases
The process by which a gas under pressure escapes from a compartment of a container to another by
passing through a small opening is called
a. effervescence
b. effusion
c. diffusion
d. sublimation
b. effusion
As a bubble of air rises from a diver’s helmet to the surface of the water, it continuously expands.
What law is illustrated?
a. Dalton’s law
b. Avogadro’s law
c. Boyle’s law
d. Charles’ law
c. Boyle’s law
A fatal condition known as “bends” occurs when a diver ascends too quickly to the surface of the
water. This is due to
a. nitrogen in the blood boiling off rapidly as its partial pressure decreases, forming bubbles
in the blood
b. lack of oxygen in water at depths of more than 15 meters
c. the solubility of oxygen gas is very much decreased at greater depths
d. the solubility of oxygen decreases in the blood as the diver ascends
a. nitrogen in the blood boiling off rapidly as its partial pressure decreases, forming bubbles
in the blood
When water is heated in a beaker, bubbles of air form on the side of the glass before the water boils.
This shows that
a. the solubility of gases in water decreases with increasing temperature
b. the solubility of gases in water increases with increasing temperature
c. the solubility of gases in water decreases with decreasing temperature
d. the solubility of gases in water increases with decreasing temperature
a. the solubility of gases in water decreases with increasing temperature
