A Lile Extra RECAP AND SUMMARY
IMF and SOLIDS & LIQUIDS
______________________________________________________________
Match the description in the first column with the term in the second column.
1
This condition eventually exists between the particles of water in the liquid and
gas states when liquid water is placed in an evacuated container and sealed. B
A boiling point
2
At an atmospheric pressure of 700 mmHg water boils at 97.7oC.
B dynamic equilibrium
3
The temperature at which the vapor pressure of a gas above the liquid is 1 atm.
C surface tension
4
The pressure exerted by the particles of a liquid in the “gas” phase.
D capillary
5
An oil that has a low rating of this term is best used at low temperatures in a car
engine, thereby permitting pistons to slide easily against cylinder walls.
E coordination number
6
A physical property exhibited by alcohol at 20oC when it spreads out on a piece
of wax paper more readily than water.
F hydrogen bonds
7
A liquid is drawn up into a thin tube by this action.
G normal boiling point
8
Type of forces holding Ar together in the liquid state.
H triple point
9
The existence of this type of IMF causes water to have a higher normal boiling
point than hydrogen sulfide.
I unit cell
10
Term given to a general type of force that enables that enables molecular
compounds to exist as liquids and solids.
J intermolecular
11
The temperature at which the solid and liquid phases of a substance are at
equilibrium and the pressure is 1 atm.
K normal melting point
12
***CO2(s) cannot sublime to form CO2(g) above this temperature.
L vapor pressure
13
***The highest temperature at which CH4 can be converted from a gas to a
liquid.
M crystalline
14
Glass is an example of a solid that shows no regular pattern of particles.
N critical temperature
15
A solid whose arrangement of particles shows a structure with lattice points only
at corners and square faces.
O dispersion forces
16
A solid whose arrangement of particles shows a regular pattern in all directions.
P primitive cubic
17
The smallest portion of a crystal that can be used to reproduce the entire
structure of the crystal.
Q viscosity
18
***The number of nearest-neighbor anions surrounding a cation in a crystal.
R amorphous
Are the following statements true or false?
22. The figure to the right could represent the phase diagram for a pure
substance.
23. According to the figure to the right, it is possible for this substance to
undergo a phase change from solid to liquid at 9atm of pressure
(Point A).
24. Significant dipole-dipole forces should exist between CCl4 and SO2.
25. The polarizability of CCl4 should be larger than that of CH4.
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A Lile Extra RECAP AND SUMMARY
IMF and SOLIDS & LIQUIDS
______________________________________________________________
26. Water collected on a well waxed surface tends to form a spherical bead. This shows that the
surface tension of water is high relative to the intermolecular forces between water an wax.
27. Oxygen freezes at a lower temperature than carbon dioxide. So, you should expect that heat of fusion of
oxygen to be greater than the heat of fusion of carbon dioxide.
28. Heat of vaporization for a liquid is always smaller than its heat of fusion.
29. A volatile substance has a high heat of vaporization.
30. Metals are materials that are shiny, ductile, and malleable.
31. A crystal lattice represents a two-dimensional array of points describing a crystalline solid.
32. A primitive cubic unit cell shows lattice points only at the corners of a cube.
33. A body-centered cubic unit cell is a primitive unit cell with the addition of a lattice point in the center of the
cube.
34. A face-centered cubic unit cell is a body-centered unit cell with the addition of lattice points at the center of
each face of the cube.
35. X-ray diffraction techniques are used to determine the spacing of layers of atoms in a solid crystal.
36. Molecular solids tend to be rigid solids.
37. An example of a covalent network solid is diamond.
38. Ionic solids show good thermal conduction.
39. Metallic solids consist of arrays of atoms of metallic elements and show good conductivity of heat.
A few final short answer questions . . .
40. The figure to the right shows a graph of the vapor pressure versus
temperature for three different molecular substances.
At the
o
temperature of 30 C, shown by a vertical line in the figure, which
substance has the greatest intermolecular forces between the molecules?
Explain.
41. In figure to the right a horizontal line shows the pressure of one
atmosphere. Which substance has the highest normal boiling point?
Explain. Assume that sodium chloride is soluble in substance B. How
would the curve for substance B change if sodium chloride is added to it
and how would this affect its boiling point? Explain.
42. In which phase(s) of a substance is (are):
(a) collisions between particles NOT occurring?
(b) particles are able to slide past one another?
(c) the average kinetic energy of particles the largest.
43. How does the polarizability of a molecule relate to the magnitude of dispersion forces? What property shown
on the periodic table helps you predict the relative magnitude of dispersion forces between chlorine, bromine,
and iodine molecules.
44. Rank the expected trend in H-bonding forces between the nitrogen atom of NH3(l) and the following
molecules: HF, H2O, and NH3.
New 2014-2015
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A Lile Extra RECAP AND SUMMARY
IMF and SOLIDS & LIQUIDS
______________________________________________________________
ANSWERS
1. B
2. A
3. G
4. L
5. Q
6. C
7. D
8. O
9. F
10. J
11. K
12. H
13. N
14. R
15. P
16. M
17. I
18. E
22. TRUE
23. FALSE
24. FALSE
25. TRUE
26. TRUE
27. FALSE
28. FALSE
29. FALSE
30. TRUE
31. FALSE
32. TRUE
33. TRUE
34. TRUE
35. TRUE
36. FALSE
37. TRUE
38. FALSE
39. TRUE
27. It takes less energy to melt O2 than to melt CO2 so it should have a lower heat of fusion.
36. Are they “stiff” and nonmalleable? Yes. But rigid usually implies “strong” too. So . . . NOPE
40. substance C; small VP means large IMF
41. high IMF means high BP. Adding NaCl means an increase in dipole-ion forces. The line would be
lower than it is (like line C) and indicate a higher BP.
42. a = solid
b = gas and liquid
c = gas
43. More electrons mean a greater electron cloud that can be distorted and it means stronger
dispersion forces. An increase of mass generally means more electrons and greater electrons
means more polarizability.
44. N−H⋯NH3 < O−H⋯NH3 < H−F⋯NH3
The strength depends on the extent of the dipole in the
H-bond.
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