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CEM 141
+2 - ANS-What is the formal charge on the sulfur in SO3?
1 - ANS-How many molecules of carbon dioxide remain at the end of the reaction?
1s2 2s2 2p6 - ANS-What is the electron configuration of a nitride ion N^3-
3 - ANS-Ammonia reacts with carbon dioxide to produce urea and water:
2NH3 + CO2 --> (NH2)2CO + H2O
Given the initial mixture of NH3 and CO2 shown to the right, assume the reaction proceeds with
100% yield.
How many molecules of urea are produced?
3.4 x 10^-19 J - ANS-Yellow light has a wavelength of 580 nm. What is the energy of one photon
of yellow light?
8.82 g - ANS-If 5.00 grams of ammonia react with excess carbon dioxide, how many grams of
urea would be produced?
AlCl3 - ANS-What is the most likely formula for the compound formed between aluminum and
chlorine?
always polar. - ANS-Draw the Lewis Structure for the molecule CH2Cl2. This molecule is:
Because both the alpha particle and the nucleus are positively charged and so the alpha particle
is repelled. - ANS-Why are alpha particles deflected by the nucleus of the atom?
Because H2 has more electrons in the bonding orbitals than in the anti-bonding orbitals,
whereas He2 has the same number in both. - ANS-Why do two hydrogen atoms interact
through covalent bonds while two helium atoms do not?
Because iodine has a larger more polarizable electron cloud. - ANS-Why is the boiling point of
iodine higher than that of bromine?
Because there is an attractive force between the two atoms. - ANS-As two atoms approach
each other why does the potential energy decrease?
BF3 - ANS-Which of these substances has a trigonal planar molecular shape?
CO2, NH3, BF3, more than one
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Both are the same. - ANS-Imagine a system composed of two different types of molecules, one
relatively light and one relatively heavy. At a particular temperature, which molecule has a lower
kinetic energy?
Both gravitational and electrostatic. - ANS-For a pencil sitting on a desk, what forces are acting
on the pencil?
Br2 because Br2 has stronger London Dispersion Forces than F2 and therefore takes more
energy to overcome the LDFs when Br2 boils. - ANS-Which substance has the highest boiling
point? (f2 or Br2)
Why?
CH3CH2NH2; hydrogen bonding interactions - ANS-Which one of the following substances
(with similar molar masses) would you expect to have the highest boiling point?
CH3CH2NH2 or CH3CH2CH3
What is the strongest bond that is overcome when the substance boils?
Cl- because it has the same number of electrons as K+ but fewer protons, so the attraction
between the electrons and nucleus are weaker. - ANS-Consider Cl- and K+. Which is larger and
why?
Decreases; the relative attraction between the protons and the outer electrons increases. -
ANS-Atomic radius _______ from left to right across a row on the Periodic table. Why?
Decreasing, because of nuclear fusion in stars. - ANS-At the present time the number of atoms
in the universe is
Energy is required. - ANS-In breaking a single chemical bond:
Energy level diagrams describe electron behavior of all elements but the Bohr model only
describes electron behavior for hydrogen; energy level diagrams do not imply distance from the
nucleus but the Bohr model does. - ANS-Why do we sue an energy level diagram rather than
the Bohr model of the atom to describe electron behavior in atoms?
Energy transfers from your skin to the water (sweat), and the energy makes the molecules
vibrate more strongly, and intermolecular forces between the water molecules are overcome
and the water evaporates. - ANS-When sweat evaporates form your skin you feel cooler. What
process is responsible for this?
Exothermic. - ANS-On a hot humid day, water in the air condenses on the outside of a cold cup.
The condensation of water is:
False - ANS-True/False: All atoms of an element are identical and have the same mass and
properties.
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CEM 141CEM 141.pdf####################################################################################CE
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9/24/2026CEM 141.pdf####################################################################################CE
141.pdfCEM 141.pdf#########################################################
CEM 141
+2 - ANS-What is the formal charge on the sulfur in SO3?
1 - ANS-How many molecules of carbon dioxide remain at the end of the reaction?
1s2 2s2 2p6 - ANS-What is the electron configuration of a nitride ion N^3-
3 - ANS-Ammonia reacts with carbon dioxide to produce urea and water:
2NH3 + CO2 --> (NH2)2CO + H2O
Given the initial mixture of NH3 and CO2 shown to the right, assume the reaction proceeds with
100% yield.
How many molecules of urea are produced?
3.4 x 10^-19 J - ANS-Yellow light has a wavelength of 580 nm. What is the energy of one photon
of yellow light?
8.82 g - ANS-If 5.00 grams of ammonia react with excess carbon dioxide, how many grams of
urea would be produced?
AlCl3 - ANS-What is the most likely formula for the compound formed between aluminum and
chlorine?
always polar. - ANS-Draw the Lewis Structure for the molecule CH2Cl2. This molecule is:
Because both the alpha particle and the nucleus are positively charged and so the alpha particle
is repelled. - ANS-Why are alpha particles deflected by the nucleus of the atom?
Because H2 has more electrons in the bonding orbitals than in the anti-bonding orbitals,
whereas He2 has the same number in both. - ANS-Why do two hydrogen atoms interact
through covalent bonds while two helium atoms do not?
Because iodine has a larger more polarizable electron cloud. - ANS-Why is the boiling point of
iodine higher than that of bromine?
Because there is an attractive force between the two atoms. - ANS-As two atoms approach
each other why does the potential energy decrease?
BF3 - ANS-Which of these substances has a trigonal planar molecular shape?
CO2, NH3, BF3, more than one
######################################################################################!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Q
CEM 141CEM 141.pdf####################################################################################CE
,######################################################################################!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Q
#################################CEM
9/24/2026CEM 141.pdf####################################################################################CE
141.pdfCEM 141.pdf#########################################################
Both are the same. - ANS-Imagine a system composed of two different types of molecules, one
relatively light and one relatively heavy. At a particular temperature, which molecule has a lower
kinetic energy?
Both gravitational and electrostatic. - ANS-For a pencil sitting on a desk, what forces are acting
on the pencil?
Br2 because Br2 has stronger London Dispersion Forces than F2 and therefore takes more
energy to overcome the LDFs when Br2 boils. - ANS-Which substance has the highest boiling
point? (f2 or Br2)
Why?
CH3CH2NH2; hydrogen bonding interactions - ANS-Which one of the following substances
(with similar molar masses) would you expect to have the highest boiling point?
CH3CH2NH2 or CH3CH2CH3
What is the strongest bond that is overcome when the substance boils?
Cl- because it has the same number of electrons as K+ but fewer protons, so the attraction
between the electrons and nucleus are weaker. - ANS-Consider Cl- and K+. Which is larger and
why?
Decreases; the relative attraction between the protons and the outer electrons increases. -
ANS-Atomic radius _______ from left to right across a row on the Periodic table. Why?
Decreasing, because of nuclear fusion in stars. - ANS-At the present time the number of atoms
in the universe is
Energy is required. - ANS-In breaking a single chemical bond:
Energy level diagrams describe electron behavior of all elements but the Bohr model only
describes electron behavior for hydrogen; energy level diagrams do not imply distance from the
nucleus but the Bohr model does. - ANS-Why do we sue an energy level diagram rather than
the Bohr model of the atom to describe electron behavior in atoms?
Energy transfers from your skin to the water (sweat), and the energy makes the molecules
vibrate more strongly, and intermolecular forces between the water molecules are overcome
and the water evaporates. - ANS-When sweat evaporates form your skin you feel cooler. What
process is responsible for this?
Exothermic. - ANS-On a hot humid day, water in the air condenses on the outside of a cold cup.
The condensation of water is:
False - ANS-True/False: All atoms of an element are identical and have the same mass and
properties.
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CEM 141CEM 141.pdf####################################################################################CE
