8) When a liquid is heated at its boiling point, the
A) ionic bonds are broken, allowing sublimation to occur.
B) temperature of the liquid decreases.
C) temperature of the liquid remains the same as long as any liquid is present.
D) temperature of the vapor phase decreases.
9) The boiling point of a liquid is 64 °C and the enthalpy change for the conversion of this liquid to the
gas is 32.21 kJ/mole. What is the entropy change for vaporization, ΔSvap?
A) 2061 J/mol*K
B) 10.9 J/mol*K
C) 503 J/mol*K
D) 96 J/mol*K
10) How much heat (kJ) is required to convert 3.12 moles of liquid benzene at 75.1°C to gaseous benzene
at 115.1°C? The following information may be useful.
b.p = 80.1ᴼC
Cm (liquid benzene) = 136.0 J/ (mol * °C)
ΔHvap = 30.72 kJ/mol
Cm (gaseous benzene) = 36.6 J/ (mol * °C)
A) 94.0
B) 101965
C) 36.8
D) 102.0
11) Which of the following compounds has the highest boiling point?
A) H2O
B) HCl
C) N2
D) Ar
12) Which of the following substances has the highest boiling point?
A) CH3–CH2–CH2–CH2–CH3
B) Ar
C) CH3–CH2–CH2–CH3
D) (CH3)2CHCH2CH3
13) Arrange the following in order of increasing boiling point.
CH3CH2OH CH3CH2CH2CH3 H3C-O-CH2CH3 CH3CH2NH2
I II III IV
A) IV < III < II < I
B) II < III < IV < I
C) I < IV < III < II
D) II < III < I < IV
14) A kitchen pressure cooker operates at 1.70 atm. The ΔHvap of water is 40.7 kJ/mol. What is the boiling
point of water in the pressure cooker?
A) 380 K
B) 373 K
C) 389 K
D) 400 K
15) Which of the following forms a molecular solid?
A) CaCl2
B) C9H8O4
C) C, graphite
D) palladium
16) Which of the following forms an ionic solid?
A) Au
B) CH3NH2
C) NH4Cl
D) N H3
17) Which type of bonding does Ca form upon solidification?
A) covalent network
B) ionic
C) metallic
D) molecular
18) Solids having no ordered long-range structure are classified as
A) amorphous solids.
B) crystalline solids.
C) nonmetallic solids.
D) covalent network solids.
19) Which is classified as an amorphous solid?
A) palladium(II) bromide
B) phosphorus tetrachloride
C) plastic
D) potassium iodide
20) Which of the following forms a molecular solid?
A) lithium chloride
B) water
C) graphite
D) gold
21) Which of the following forms a metallic solid?
A) gold
B) potassium bromide
C) quartz
D) plastic
22) Which of the following compounds forms a covalent network solid?
A) Na
B) diamond
C) N2
D) CS2
23) Which of the following compounds forms an ionic solid?
A) water
B) carbon dioxide
C) potassium bromide
D) zince
36
24) Which type of bonding does sucrose form upon solidification?
A) metallic
B) amorphous
C) molecular
D) anionic
25) What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 139
pm?
A) 197 pm
B) 393 pm
C) 556 pm
D) 1110 pm
26) Aluminum has a face-centered cubic structure and has a density of 2.70 g/cm3. What is its atomic
radius?
A) 143 pm
B) 286 pm
C) 405 pm
D) 1150 pm
27) A certain metal crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if
the atomic radius of the metal is 134 pm?
A) 189 pm
B) 268 pm
C) 309 pm
D) 379 pm
28) Barium has a radius of 224 pm and crystallizes in a body-centered cubic structure. What is the edge
37
length of the unit cell?
A) 259 pm
B) 317 pm
C) 448 pm
D) 517 pm
29) Manganese crystallizes in a body-centered cubic structure. What is the coordination number of each
atom?
A) 4
B) 6
C) 8
D) 12
30) KI crystallizes in a cubic unit cell with I– ions on each corner and each face. How many K+ and I– ions
are in each unit cell of KI?
A) 1 K+ ion and 1 I– ion
B) 2 K+ ions and 2 I– ions
C) 4 K+ ions and 4 I– ions
D) 8 K+ ions and 8 I– ions
31) How many Br– ions are around each Na+ ion in NaBr, which has a cubic unit cell with Br– ions on
each corner and each face?
A) 1
B) 4
C) 6
D) 8
32) Which of the following is an allotrope of carbon?
A) diamond
B) glass
C) coal
D) carbon monoxide
33) The layers of graphite are held together by
A) covalent bonds.
B) ion-ion forces.
C) London dispersion forces.
D) cationic forces.
34) Diamond is held together by
A) covalent bonds.
B) ion-dipole forces.
C) van der Waals forces.
D) ionic forces.
35) ________ are used as a battery electrode material.
A) Buckyballs
B) Graphite
C) Carbon
D) Sucrose molecules
36) Which transition could occur if a solid is heated at a pressure above the triple point pressure?
A) vaporization
B) deposition
C) melting
D) sublimation
11.3 Short Answer Questions
1) The property of a liquid that is a measure of the liquid’s resistance to increase its surface area is
________.
2) Of C2H5OH and C3H5(OH)3 the one expected to have the higher viscosity is ________, and the one
expected to have the higher surface tension is ________.
3) The phase change H2(g) → H2(s) is called ________, and the enthalpy change, ΔH, for this phase
change has a ________ sign.
4) Of C2H5OH and C3H5(OH)3 the one expected to have the higher vapor pressure is ________, and the
one expected to have the higher boiling point is ________.
5) The solids formed by Na, Na2O2, SiO2, and N2 are classified as ________, ________, ________, and
________, respectively.
6) Rubber is classified as an ________ solid, whereas diamond is classified as a ________ solid.
7) A low-melting crystalline compound that does not conduct electricity in the solid or liquid state is
classified as a ________ solid.
8) First-order diffraction of X-rays with d = 154.2 pm at an angle of 32.5° is caused by layers of atoms in a
crystalline solid with a spacing of ________ pm.
9) Layers of atoms having a spacing of 105 pm will diffract X-rays with d = 154.2 pm at an angle of
________ degrees.
10) The cubic closest-packed arrangement of atoms is the same as which cubic unit cell?
11) The two most efficiently packed unit cells have the hexagonal closest-packed and the ________ the
atomic arrangements.
12) The coordination number of each atom in a body-centered cubic unit cell is ________.
13) The cubic unit cell in which the radius of an atom is 31/2 d/4, where d is the unit cell edge length, is
the ________ unit cell.
14) A certain metal can exist in two different cubic cells, body-centered and face-centered cubic. Which
unit cell will have the greater density?
15) Ni has a face-centered unit cell. The number of Ni atoms in the unit cell is ________.
16) A compound having A ions on each corner and B ions on each face of a cubic unit cell has the
empirical formula ________.