CAS CH 62048

subject Type Homework Help
subject Pages 10
subject Words 1276
subject Authors American Chemical Society

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page-pf1
Looking at the data in this chart, which observations are correct?
I. The percentage of the population that are undernourished in developing countries has
fallen steadily since 1969.
II. The largest decline in undernourished population was in Asia and the Pacific.
III. No region has seen an increase in the undernourished population in any time period
after 1969.
A. I and II
B. I and III
C. II and III
D. I, II, and III
Based on this reaction and its energy profile,
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CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
the reaction
A. is exothermic.
B. is endothermic.
C. has a high activation energy.
D. violates the first law of thermodynamics.
Which ion is correctly matched with its important biological function?
A. I and X
B. II and Z
C. III and Y
D. IV and W
page-pf3
Which practices might be described as carbon sequestration?
I. Planting trees
II. Deforestation
III. Pumping carbon dioxide deep into the ocean
IV. Increasing combustion of fossil fuels
A. I and II only
B. II and III only
C. III and IV only
D. I and III only
Blowing agents are gases, or a compound that releases a gas, that are added to polymers
in the manufacture of a foamed plastic. Which statement is not true?
A. At one time, CFC's were used as blowing agents.
B. Gaseous pentane is now often used.
C. The DOW 100% CO2 technology uses carbon monoxide.
D. The use of pentane is hazardous because it is highly flammable.
page-pf4
What percentage of a radioactive isotope would remain after three half-lives?
A. 6.3%
B. 12.5%
C. 25.0%
D. 50.0%
This is a structural formula for propylene.
Which of these does not represent a possible arrangement of monomers within
polypropylene?
A.
B.
C.
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D.
The following molecules contain only single bonds.
NH3(g) + 3F2(g) → NF3(g) + 3 HF(g)
The bond energies are: N H 391 kJ/mol; F F 158 kJ/mol; N F 272 kJ/mol; H F
566 kJ/mol. Which is the heat evolved or absorbed per mole of NH3 that reacts with F2?
A. +289 kJ/mol
B. +867 kJ/mol
C. -289kJ/mol
D. -867 kJ/mol
What do the letters HDPE represent?
A. high definition polyethylene
B. high density polyethylene
C. hard durable polyethylene
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D. highly ductile polyethylene
The greenhouse effect refers to the process by which
A. atmospheric oxygen and nitrogen absorb heat radiated by Earth.
B. atmospheric nitrogen absorbs ultraviolet radiation radiated by Earth
C. atmospheric gases trap and return infrared radiation radiated by Earth.
D. greenhouse gases absorb ultraviolet radiation from the Sun, warming the molecules.
What is the effect of the absorption of infrared energy on matter?
A. It excites bonding electrons.
B. It increases molecular rotation.
C. It breaks chemical bonds.
D. It increases the vibration of chemical bonds.
page-pf7
Which is a known risk associated with nuclear power plants?
A. The electricity produced will be radioactive.
B. The water used to cool the system will become radioactive.
C. The workers will have higher risks for cancer than the standard population.
D. The cooling water source can suffer thermal pollution.
The pH of rain water falling through an unpolluted atmosphere is closest to:
A. 4.7
B. 5.4
C. 7.0
D. 8.7
page-pf8
The family of compounds known as steroids share a common molecular framework of
17 carbon atoms that are arranged into four rings. Which is a representation of this
common molecular framework?
A.
B.
C.
D.
Consider these three compounds.
Which are isomers?
A. I and II only
B. I and III only
C. II and III only
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D. I, II, and III
Which of the following is most biologically damaging type of radiation?
A. UV-A
B. UV-B
C. UV-C
D. Infrared
According to the graph below,
the net United States import of petroleum drastically decreased during the years
A. 1970 to 1977.
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B. 1973 to 1975.
C. 1977 to 1982.
D. 1985 to 1990.
The general term for plant matter such as trees, grasses, agricultural crops, or other
biological material is
A. biomass.
B. cornstarch.
C. diesel.
D. fossil fuel.
The nitrogen-containing bases in DNA are attached by covalent bonds to a
A. sugar.
B. complementary base.
C. protein.
D. phosphate.
page-pfb
Which functional group does this molecule contain?
A. acid
B. alcohol
C. amine
D. ester
The opposite of a galvanic cell is
A. a battery.
B. an electrolytic cell.
C. a fuel cell.
D. a photovoltaic (solar) cell.
page-pfc
In the famous equation E = mc2, the symbols represent:
A. E = Einstein, m = matter, c = speed of light
B. E = energy, m = mass, c = characteristic of the particle
C. E = Einstein, m = meters, c = conversion
D. E = energy, m = mass, c = speed of light
Which is not considered to be low-level radioactive waste?
A. clothing for workers administering nuclear medicine
B. smoke detectors
C. spent fuel rods
D. radioactive pharmaceuticals
The heat of combustion of methane, CH4, is 50.1 kJ/g. How much heat would be
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generated if 1.00 mol of methane undergoes complete combustion?
A. 0.32 kJ
B. 3.12 kJ
C. 601 kJ
D. 804 kJ
CO2 emissions in China declined by 9% over the five-year period ending in 2000. If
5.00 x 108 metric tons (t) of CO2 was emitted in 1995, how much CO2 was released in
2000?
A. 4.55 x 109 t
B. 4.55 x 108 t
C. 4.50 x 108 t
D. 4.55 x 107 t
Chlorofluorocarbons rise to the stratosphere and
A. react directly with stratospheric ozone to destroy it.
page-pfe
B. interact with UV energy to produce free radicals that destroy ozone.
C. interact with UV energy to produce free radicals that react with oxygen to create
ozone.
D. react with free radicals to remove carbon dioxide.
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
Amino acids are compounds that contain both amine and organic acid functional
groups. Which compound is an amino acid?
page-pff
A.
B.
C.
D.
What energy change is associated with the reaction to obtain one mole of H2 from one
mole of water vapor? The balanced equation is 2 H2O(g) → 2H2(g) + O2(g) and the
relevant bond energies are: H H = 436 kJ/mol; H O = 467 kJ/mol; O O = 146
kJ/mol; O O = 498 kJ/mol.
A. -249 kJ
B. +249 kJ
C. -436 kJ
D. +436 kJ
page-pf10
The chemical properties of the elements are chiefly due to the number
A. of protons.
B. and distribution of the outer electrons.
C. and distribution of the inner electrons.
D. and distribution of the neutrons.

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