Chapter 10 Review Packet
Name______________________________________
1.
If water and carbon dioxide molecules did interact, what major intermolecular force will
exist between these molecules?
a)
Hydrogen bonding
b)
London dispersion
c)
Dipole-dipole forces
2.
Which of the following molecule pairs are not involved in hydrogen bonding?
a)
HCOOH, H2O
b)
H2O, NH3
c)
CH3OH, CH3COOH
d)
H2 and I2
3.
Arrange the following molecules in order of decreasing intermolecular interaction:
SO2, Cl2, CH3OH, CH3NH2
a)
b)
c)
d)
CH3OH > CH3NH2 > SO2 > Cl2
Cl2 > SO2 > CH3OH > CH3NH2
SO2 > CH3NH2 > CH3OH > Cl2
CH3NH2 > CH3OH > SO2 > Cl2
4.
Knowing that solutes with a certain polarity (or absence of it) are best dissolved in
solutions with similar polarity, which of the following solvents would be optimal for the
solvation of CH3COOH?
a)
CH4
b)
CH3OH
c)
C2H6
d)
C6H6
5.
Which of the following molecules interact primarily through London-dispersion forces?
a)
SO2
b)
CCl4
c)
CH2Cl2
d)
H2S
6.
Which of the following has the highest boiling point?
a)
H2O
b)
HF
c)
HI
d)
HBr
7.
Surface tension is due to the:
a)
liquid molecules being more attracted to surrounding surface molecules than other
liquid molecules
b)
liquid molecules being as attracted to surrounding molecules as to other liquid
molecules
c)
liquid molecules being more attracted to other liquid molecules than surrounding
molecules
d)
liquid molecules being attracted only to surrounding molecules
8.
Which of the following liquids will be the most viscous?
a)
C3H8
b)
C6H6
c)
CH4
d)
C2H6
9.
In the liquid state, molecules:
a)
are100% hydrogen bonded to their neighbors.
b)
are part of a crystal lattice.
c)
are frozen in space.
d)
are considerably restricted in movement.
10.
Which of the following liquids would show a convex meniscus when placed in a glass
tube?
a)
CH3OH(ℓ)
b)
H2O(ℓ)
c)
CHCl3(ℓ)
d)
BF3(ℓ)
11.
The smallest repeating unit of the lattice is called:
a)
unit cell
b)
unit lattice
c)
cell
d)
unit crystal
12.
Which of the following types of solids exist as crystals?
a)
ionic solids
b)
atomic solids
c)
molecular solids
d)
metallic solids
13.
The successive packing pattern for an hcp cell is which one of the following?
a)
ABABAB
b)
ABAABA
c)
ABCABC
d)
ABCCBA
14.
X-rays with a particular wavelength were used to analyze a crystalline solid. Assuming
n = 1, and knowing that the distance between the planes of atoms, producing a diffraction
with an angle = 20.0º, is 200 pm, calculate the frequency of the X-rays.
a)
365
b)
6.22 x 1015
c)
0.110
d)
2.19 x 1018
15.
Conducting electrons in metals are situated in:
a)
Localized orbitals
b)
s-orbitals
c)
Metallic orbitals
d)
Conduction bands
16.
The vapor pressure of 1-propanol at 14.7C is 10.0 torr. The heat of vaporization is
47.2 kJ/mol. Calculate the vapor pressure of 1-propanol at 52.8C.
a)
100. torr
b)
20.0 torr
c)
200. torr
d)
600. torr
ln PT1
PT2
ln 10.0
PT2
=
=
ΔHvap
R
1  1
T2
T1
47,200 J/mol
8.3145 J/mol
ln(10/PT2) = 2.304
10/PT2 = 0.0999
PT2 = 100. torr
__1__  __1___
326.0 K
287.9 K
17.
The difference between interstitial alloy and substitutional allow is that in substitutional
alloys:
a)
Some atoms of one element are replaced by atoms of another element
b)
Atoms of one element are inserted in the spaces between the atoms of the other
element
c)
Atoms of one element fuse with the atoms of the other element
d)
Three elements, rather than two, are combined to form the alloy
18.
Which one of the following decreases as the strength of the attractive intermolecular
forces increases?
a)
The heat of vaporization.
b)
The normal boiling temperature.
c)
The extent of deviations from the ideal gas law.
d)
The sublimation temperature of a solid.
e)
The vapor pressure of a liquid.
19.
Which one of the following statements about liquids and solids is generally false?
a)
The rate of diffusion is lower in solids.
b)
The density of solids is higher.
c)
The compressibility of liquids is higher.
d)
Liquids have higher vapor pressures.
e)
The heat of vaporization is less than the heat of fusion.
20.
Which of the following is a correct listing in terms of increasing boiling point?
a)
CH4 < NH3 < H2O < HF
b)
CH4 < NH3 < HF < H2O
c)
CH4 < HF < NH3 < H2O
d)
HF< H2O < NH3 < CH4
e)
CH4 < HF < H2O < NH3
21.
The boiling points of the halogens increase from F2 to I2. What type of intermolecular
forces are responsible for this trend?
a)
permanent dipole
b)
hydrogen bonding
As atomic size increases, LD forces
c)
ion-ion attraction
become increasingly more important.
d)
London dispersion forces
e)
ion-dipole attraction
22.
Which of the following statements is true about p-type silicon?
a)
It is produced by doping Si with P or As.
b)
Electrons are the mobile charge carriers.
c)
It does not conduct electricity as well as pure Si.
d)
All are true.
a. is incorrect because it produces an n-type semiconductor.
e)
None is true.
b. is incorrect because the charge carriers are holes in a p-type.
c. is incorrect because it would conduct better than pure Si.
23.
Doping Se with As would produce a(n) _______________ semiconductor with
_____________ conductivity compared to pure Se.
a)
n-type, increased
As has one less valence electron than Se so the
b)
n-type, decreased
resulting semiconductor would be a p-type. This
c)
p-type, increased
would increase the conductivity due to holes that
d)
p-type, decreased
the electrons can jump into.
e)
intrinsic, identical
24.
A material is made from Al, Ga, and As. The mole fraction of each element is 0.25, 0.26,
and 0.49, respectively. This material would be
a)
a metallic conductor because Al is present.
b)
an insulator.
Twice as much As would seem that the material
c)
a p-type semiconductor.
was doped with Al and Ga. Because Al and Ga
d)
an n-type semiconductor.
have fewer valence electrons than As, it would
e)
none of the above
make this a p-type.
25.
Which of the following statements about superconductors is false?
a)
They conduct electricity without wasting heat energy.
b)
A class of high-temperature superconductors is called perovskites.
c)
Good conductivity, efficiency, and ductility are reasons why ceramic materials are
used in superconductors. Ceramics are brittle, not ductile.
d)
High-temperature superconductors contain copper, oxygen, a lanthanide metal,
and an alkaline earth metal.
e)
All of these are true.
26.
Which of the following statements about phase changes are true?
I.
No temperature change is observed during a phase change.
II.
Vaporization is an exothermic process. EXOTHERMIC
III.
When a phase change occurs, no energy is transferred to or from the
substance. IT TAKES ENERGY TO BREAK IMF’S!!
IV.
When cooling a given amount of a substance, the rate at which cooling
occurs is a function of .the mass of the substance and its specific heat.
V.
The heat of fusion for ice would determine how much energy would
be required to change the temperature of a 10-g block of ice from
20°C to 2°C. IT WOULD BE NECESSARY TO KNOW THE
SPECIFIC HEAT OF ICE, NOT THE HEAT OF FUSION!
a)
b)
c)
d)
e)
I and III
I and IV
II and III
II, III, and IV
IV only
For questions 27 and 28, use the phase diagram for compound X below:
27.
The normal boiling point of X is most likely:
a)
21°C
b)
47°C
c)
73°C
d)
18°C
e)
0°C
28.
How will the melting point of X change with increased pressure?
a)
increase
b)
decrease
c)
remain the same
d)
there is not enough information given
e)
increase and then decrease
29.
How much energy is needed to convert 64.0 grams of ice at 0.00C to water at 75.0C?
specific heat capacity of water = 4.18 J/gC
Hvap of water = 2258 J/g
specific heat capacity of ice = 2.1 J/gC
Hfusion of water = 333 J/g
a) 10.1 kJ
b) 20.7 kJ
c) 31.4 kJ
Melt water.
q = ΔHfusgrams
q = (333 J/g) (64.0 g)
q = 21,300 J = 21.3 kJ
Heat water from 0C to 75C.
q = mcΔT
q = (64.0 g) (4.18 J/gC) (75C  0C))
q = 20,100 J = 20.1 kJ
Add to get the energy needed: 21.3 kJ + 20.1 kJ = 41.4 kJ
d) 41.4 kJ
e) 65.8 kJ
30.
31.
Which of the compounds below is an example of a network solid?
a) S8 (s)
b) SiO2 (s)
c) MgO (s)
d) NaCl (s)
e) C25H52 (s)
How much heat is required to change the temperature of a 10.0-gram ice cube from
15C to 132C?
32.
Use the band model to describe differences between insulators and conductors.
The band model or molecular orbital (MO) model for metals is a molecular model for
metals in which the electrons are assumed to travel around the metal crystal in molecular
orbitals formed from the valence atomic orbitals of the metal atoms. In this model, the
electrons are assumed to travel around the metal crystal in molecular orbitals formed
from the valence atomic orbitals of the metal atoms. When many metal atoms interact, as
in a metal crystal, the large number of resulting molecular orbitals become more closely
spaced and finally form a virtual continuum of levels, called bands. This existence of
empty molecular orbitals close in energy to filled molecular orbitals explains the thermal
and electrical conductivity of metal crystals. Metals conduct electricity and heat very
efficiently because of the availability of highly mobile electrons.
The difference between insulators and conductors comes in the proximity of the
molecular orbitals. Metals have MO's that are very close together. The band model is
used to explain heat and electrical conduction. In this model, mobile electrons are
furnished when electrons in filled molecular orbitals are excited into empty ones. These
conduction electrons are free to travel throughout the metal crystal. Nonmetals have a
wide gap between its MO's. As a result, their electrons cannot be excited into empty
MO's. Therefore, they do not conduct heat and electricity in an appreciable manner.
33.
How can an n-type semiconductor be produced from pure germanium? Explain.
To produce an n-type semiconductor, dope Ge with a substance that has more than 4
valence electrons, (a group 15 element). Phosphorus or arsenic are a couple of
substances which would produce n-type semiconductors when they are doped into
germanium.
34.
What would be the shape of the meniscus of water in a polyethylene tube? (Polyethylene
can be represented as CH3(CH2)nCH3, where n is a large number on the order of 1000.)
Justify your answer.
Polyethylene is a nonpolar substance. The H2O-H2O attraction (cohesive force) is
stronger than the H2O-polyethylene attraction (adhesive force) because of hydrogen
bonding in the former and only LDF in the latter. Thus, the meniscus will have a convex
shape.
35.
How much heat is given off when 164 g of steam at 350.C is cooled to ice at 125C.
9.11 mol H2O
36.
Order the following compounds from largest to smallest enthalpy of fusions:
H2O, CO2, MgO
(Justify your answer!)
H2O has hydrogen bonding as well as dipole and LDF. CO2 has is nonpolar and has only
LDF. MgO is ionic. Ionic is the strongest force, then hydrogen bonding, and finally
LDF. Thus the order of largest to smallest forces will be MgO, H2O, and CO2. As
intermolecular forces decrease, the enthalpy of fusions decrease. Therefore, the order
from largest to smallest enthalpy of fusions: MgO, H2O, CO2
37.
How much heat is necessary to melt 175.32 g of sodium chloride at 801C?
(The heat of fusion of sodium chloride is 28.16 kJ/mole.)
28.16 kJ
1 mol NaCl
1 mol NaCl
175.32 g NaCl
58.443 g NaCl
=
84.476 kJ
Remember:
*As IMF's increase, all properties (b.p., m.p., viscosity, ...) will also increase EXCEPT
vapor pressure which will decrease.
*Know how to determine LDF, dipole-dipole, and H-bonding.
*LDF's become more important as the SIZE of the atom increases.
*Understand cohesive and adhesive forces which produce either a convex meniscus or a
concave meniscus.
*Know that "normal" means at 1 atmosphere of pressure
and 1 atm = 760 mm Hg = 101.3 kPa
*Know that "standard pressure" = 1 atm
*Understand the trends in the diagrams of the alkanes and the b.p.’s of the hydrogen
compounds of Groups 14-17.
*Understand phase diagrams and how to read them.
*Understand the trend that density follows during phase changes.
*Know the difference between substitutional and interstitial alloys and examples of each.
*Know the difference between n-type and p-type semiconductors and how to form each.
*Know how to calculate enthalpy changes (Like a 10.0-g ice cube at 15C to 150. C)
*Understand the band model pertaining to thermal and electrical conductivity of metals.