Semiconductors are more effective than metals as converters of solar radiation into
electricity because
A. it is easier for the atoms of a semiconductor to absorb solar energy and to move from
place to place within the solid, thereby conducting electricity.
B. the energy contained in sunlight gives the valence electrons in the semiconductor
atoms the extra energy they need to “flow” throughout the solid.
C. metals melt much too easily under direct sunlight and, as liquids, lose their ability to
conduct electricity.
D. solar radiation has sufficient energy to knock electrons completely off the metal
surface, making it impossible for the electrons to “flow” from atom to atom and conduct
electricity.
If we assume that the top of Mt. Everest is the highest land mass on earth, hikers who
scale its summit are standing in the
A. mesosphere.
B. stratosphere.
C. troposphere.
D. ozone layer.
The current through a wire is most closely related to the
A. energy of the electrons flowing through the wire.
B. type of electrons flowing through the wire.
C. rate of electron flow through a wire.
D. oxidation potential of the electrons flowing through the wire.
In a fuel cell,
A. there is oxidation, but no reduction.
B. reduction takes place at the cathode.
C. there is direct conversion of mechanical energy into electricity.
D. a chemical reaction produces heat, which then produces electricity.
For what purpose was the Haber-Bosch process developed?
A. reduction of SOx in coal burning power plant emissions
B. reduction of NOx in vehicle emissions
C. nitrification of soil
D. production of ammonia
Hydrogen gas (H2) is a promising alternative to fossil fuels. How many molecules are
present in 1.0 kg of hydrogen gas?
A. 3.0 1023
B. 6.0 1023
C. 3.0 1026
D. 6.0 1026
Over the very long run, the energy source that has the greatest potential to meet
humanity’s needs is
A. coal.
B. hydropower.
C. renewable biomass.
D. solar (the sun).
Evaluate the ratio MH+ (pH 3) / MH+ (pH 7).
A. 0.0001
B. 0.001
C. 0.429
D. 10,000
Why are automobiles a contributor to acid rain when there is no sulfur in gasoline to
make SOx?
A. This is incorrect because there is sulfur in gasoline.
B. Catalytic converters contain sulfur compounds.
C. Hydrocarbons contribute to acid rain, also.
D. Nitrogen from the atmosphere combines with oxygen in the hot engine to make
NOx.
Which statement is false with respect to carbohydrates?
A. They are made up of carbon, hydrogen, and oxygen in a 1:2:1 ratio.
B. They are made from carbon dioxide and water by the process of photosynthesis.
C. They are metabolized in the body to produce energy.
D. They are the cause of obesity and should be eliminated from a healthful diet.
Very small mercury batteries have been made and used in a multitude of applications.
Why have they been replaced by other kinds of batteries for most applications?
A. Mercury has become far too expensive to use in batteries.
B. Mercury is poisonous and difficult to dispose of.
C. These batteries cannot generate enough current for any modern devices.
D. Though they may be made very small, they are far too heavy to use in most
applications.
For this line-angle drawing, which condensed structural formula is correct?
A. CH3CH2CH2CH2OH
B. CH3CH(CH3)CH2OH
C. CH3CH(OH)CH2CH3
D. CH(CH3)2CH2OH
Which component of the air is an element?
A. H2O
B. NO2
C. O2
D. CO2
Which is not a reason for the decline in the reliance on nuclear power for electricity
generation in the United States over the last 30 years?
A. a lack of available nuclear fuel
B. the need for enhanced safety training for workers
C. the need to retrofit old plants
D. an increase in the required number of qualified personnel
The majority of N2O molecules in the atmosphere come from
A. bacterial removal of nitrate ions (NO3) from soil.
B. burning of fossil fuels.
C. decaying vegetable matter.
D. landfills.
Smokestacks at these plants release sulfur oxides and carbon dioxide into the air:
A. coal-burning plants.
B. nuclear plants.
C. both coal-burning and nuclear plants.
D. neither coal-burning nor nuclear plants.
Which equation correctly shows the first step in the formation of polyethylene
terephthalate (PET) by the process of condensation polymerization?
A.
B.
C.
D.
Consider this table.
How many pounds of plastics were produced per person in 2003?
A. 0.369
B. 3.69
C. 36.9
D. 369
Which is not a reason for the decline in the reliance on nuclear power for electricity
generation in the United States over the last 30 years?
A. a lack of available nuclear fuel
B. the need for enhanced safety training for workers
C. the need to retrofit old plants
D. an increase in the required number of qualified personnel
Which functional group contains a nitrogen atom?
A. alcohol
B. amine
C. ester
D. ether
In general, a modern hybrid vehicle is less polluting than a standard vehicle because it
runs on both a
A. gasoline engine and an electric motor run by a rechargeable battery.
B. gasoline engine and a fuel cell.
C. fuel cell and an electric motor run by a rechargeable battery.
D. gasoline engine and a cleaner diesel engine.
Which diagram(s) best represent(s) only individual atoms?
A. I only
B. II only
C. III only
D. IV only
E. II and III only
The quantity 0.0000064 g expressed in scientific notation is:
A. 6.4 x 106 g
B. 6.4 x 106 g
C. 6.4 x 107 g
D. 6.4 x 107 g
A catalytic effect or acceleration of a reaction can occur in the __________ of an
enzyme.
A. DNA
B. RNA
C. substrates
D. active site
“Hard” water in parts of the Midwest may have a calcium ion concentration as high as
400 ppm. What is this calcium ion concentration when expressed as a percentage?
A. 40%
B. 4%
C. 0.4%
D. 0.04%
When it reaches its largest size, the ozone hole over the Antarctic is
A. about as large as North America.
B. about the same size as France.
C. smaller than Iceland.
D. about the same size as Canada.
Most polyatomic ions
A. have a negative charge.
B. are composed of a total of two atoms.
C. are cations.
D. contain sulfur atoms.
Based on this graph, which group of economies is predicted to have the largest energy
consumption in 2010?
A. mature market economies
B. emerging economies
C. transitional economies
D. impossible to say
All of the energy we need to run our bodies comes from the food we eat. Which
statement is false concerning this energy consumption?
A. Metabolism reverses the process of photosynthesis and produces energy from
glucose.
B. More oxygen is required to burn one gram of a fatty acid than to burn one gram of
glucose.
C. Proteins are not used by the body to provide energy.
D. The body converts glucose into carbon dioxide and water in one fast reaction.
Which of the following compounds is useful for putting out fires and does not deplete
stratospheric ozone concentrations?
A. Halon-1211
B. CFC-113
C. HFCs
D. Methyl Bromide
Although all aspirin tablets contain the same active ingredient, acetylsalicylic acid, not
all aspirin tablets are the same. Which is not a possible reason for this difference?
A. They contain fillers and bonding agents that may vary, depending on the
manufacturer.
B. Some may contain weak bases that act as buffers to reduce the natural acidity of the
aspirin.
C. Some may be coated to keep them intact until they reach the intestine.
D. Some may contain the inactive optical isomer in the preparation.
Which square(s) contain(s) only one or more compounds?
A. I only
B. II only
C. I and IV only
D. II and III only
Water has one of the highest specific heats of any known liquid. This means that the
temperature of a water sample _____ with the input of a _____ amount of energy.
A. decreases greatly; small
B. decreases only slightly; large
C. increases only slightly; large
D. increases greatly; small
Oxygenated gasolines are blends of petroleum-derived compounds with
oxygen-containing compounds. Which of the following oxygenated compounds has
been discontinued in some states because of potential health risks?
A. ethanol
B. methanol
C. MTBE
D. methane