001 Version Quiz 6 sparks (50990)
O
H
A
H
IMForces
001 1.0 points
What would be the most signicant type of
intermolecular forces in a liquid sample of
uoroform (CHF3 )?
Consider the two water molecules
This print-out should have 8 questions.
Multiple-choice questions may continue on
the next column or page nd all choices
before answering.
1
B
O
H
H
Which statement is correct?
1. The hydrogen bond B is stronger than
the covalent bond A.
1. dipole-dipole correct
2. The hydrogen bond A is stronger than
the covalent bond B.
2. covalent
3. hydrogen bonding
3. The covalent bond A is stronger than the
hydrogen bond B. correct
4. dispersion
4. The covalent bond B is stronger than the
hydrogen bond A.
CIC T05 18
002 1.0 points
Explanation:
+
O
H
A
H
Explanation:
London forces, dispersion forces, van der
Waals or induced dipoles all describe the same
intermolecular force. London forces are induced, short-lived, and very weak. Molecules
and atoms can experience London forces because they have electron clouds. London
forces result from the distortion of the electron cloud of an atom or molecule by the
presence of nearby atoms or molecules.
Permanent dipole-dipole interactions are
stronger than London forces and occur between polar covalent molecules due to charge
separation.
H-bonds are a special case of very strong
dipole-dipole interactions. They only occur
when H is bonded to small, highly electronegative atoms F, O or N only.
Ion-ion interactions are the strongest due to
extreme charge separation and occur between
ionic molecules. They can be thought of as
both inter- and intramolecular bonding.
CHF3 is a polar molecule that does not contain H bonds; therefore, dipole-dipole forces
will be the most signicant type of intermolecular forces present.
5. ionic
B
O
H
+
H
A is a covalent bond while B is a hydrogen
bond. Covalent bonds are much stronger than
H-bonds.
Mlib 04 2065
003 1.0 points
Which of the following can be expected to
exhibit the strongest hydrogen bonding in the
liquid state?
1. CH3 CH3 (ethane)
2. CH3 OH (methyl alcohol) correct
3. CH4
4. CH3 COCH3 (acetone)
5. CH3 OCH3 (dimethyl ether)
Explanation:
Version 001 Quiz 6 sparks (50990)
H-bonds are a special case of very strong
dipole-dipole They interactions. only occur
when H is bonded to small, highly electronegative atoms F, O or N only.
The structure is
H
H
C
O
H
H
Methyl alcohol is the only molecule given that
has H bonded to N, O, or F (O in this case).
Mlib 05 0023
004 1.0 points
Freezing water is what kind of process?
1. endothermic
2. Neither of these
2
melted to a liquid.
Msci 15 0009
006 1.0 points
Heat ow is considered positive when heat
ows (into, out of) a system; work is considered positive when work is done (by, on) a
system.
1. into; on correct
2. out of; on
3. out of; by
4. into; by
Explanation:
Heat ow q is considered positive when heat
ows into a system. Work w is considered
positive when work is done on a system.
3. exothermic correct
Explanation:
Freezing requires the removal of heat from
the water. This is exothermic.
Sparks phase change 001
005 1.0 points
What happens when energy is added to a
sample of ice at 0 C?
1. The temperature of the sample increases
while the ice melts.
2. None of the other answers is correct.
3. The sample remains solid and its temperature decreases.
4. The temperature of the sample remains
constant while the ice melts. correct
5. The temperature of the sample decreases
while the ice melts.
Explanation:
Energy is being added, so the process is
endothermic. Energy is required to melt a
solid. As energy is added the temperature
remains constant until all of the solid has
DAL 0301 01a
007 1.0 points
WITHDRAWN
ChemPrin3e T06 10
008 1.0 points
A CD player and its battery together do 500
kJ of work, and the battery also releases 250
kJ of energy as heat and the CD player releases 50 kJ as heat due to friction from spinning. What is the change in internal energy of
the system, with the system regarded as the
battery and CD player together?
1. 800 kJ correct
2. +200 kJ
3. 750 kJ
4. 700 kJ
5. 200 kJ
Explanation:
Heat from the CD player is 50 kJ.
Heat from the battery is 500 kJ.
Work from both together on the surround-
Version 001 Quiz 6 sparks (50990)
ings is 250 kJ.
This question is testing your ability to see
what the system is, and then look at ONLY
the energy ow for the system. Here the system is the battery and the CD player together.
U = q + w
= [50 kJ + (250 kJ)] + (500 kJ)
= 800 kJ
3