Practice Quiz

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Question 1

Helium atoms do not combine to form He2 molecules, yet He atoms do attract one another weakly through ________.

a. dipole-dipole forces
b. ion-dipole forces
c. dispersion forces
d. dipole-induced dipole forces
e. hydrogen bonding

Question 2
Given the following liquids and their boiling points, which has the highest vapor pressure at its normal boiling point?
a. ethanol, bp = 78oC
b. methanol, bp = 65oC
c. water, bp = 100oC
d. benzene, bp = 80oC
e. The vapor pressures of each of the liquids at its normal boiling point would be the same.

Question 3
Which of the following atoms does not participate in hydrogen bonding?
a. S
b. O
c. F
d. N

Question 4
Which property of water allows a razor blade to float on it without sinking?
a. viscosity
b. surface tension
c. density
d. specific heat
e. triple point

Question 5
Which one of the following substances crystallizes as a molecular solid?
a. KI
b. SiO2
c. Sn
d. CH3OH
e. Al2(SO4)3

Question 6
Which one of the following crystallizes in a metallic lattice?
a. C
b. NaMnO4
c. K
d. LiClO4
e. K2Cr2O7

Question 7
A liquid boils when its ________.
a. vapor pressure is exactly 1 atmosphere
b. vapor pressure is equal to, or greater than, the external pressure pushing on it
c. temperature is equal to 273 K (standard temperature)
d. temperature is greater than room temperature

Question 8
The heat capacity for liquid water is 4.18 J/g oC, and the heat of vaporization is 40.7 kJ/mol. How many joules of heat must be provided to convert one gram of liquid water at 67oC into one gram of steam at 100oC?
a. 22.6 kJ
b. 40.8 kJ
c. 2.2 kJ
d. 2,400 J
e. 40.8 J

Question 9
Use the graph of vapor pressure to determine the normal boiling point of O2.

a. 92 K
b. 90 K
c. 88 K
d. 84 K
e. O2 doesn't boil because it is always a gas.

Question 10
Octane is a liquid component of gasoline. Given the following vapor pressures of octane at various temperatures, estimate the boiling point of octane in Leadville, Colorado, where the atmospheric pressure is 496 mmHg.

400 mmHg at 104oC
500 mmHg at 111oC
600 mmHg at 117oC
700 mmHg at 122oC
760 mmHg at 125oC
a. 125oC
b. 120oC
c. 115oC
d. 110oC
e. 105oC

Question 11
Which of the following compounds should be soluble in CCl4?
a. NaCl
b. H2O
c. NaOH
d. C8H18
e. None of the above

Question 12
Which of the following gives the molarity of a 17.0 percent by mass solution of sodium acetate, CH3COONa (molar mass = 82.0 g/mol), in water? The density of the solution is 1.09 g/mL.
a. 2.26 x 10-6 M
b. 0.207 M
c. 2.07 M
d. 2.26 M
e. 2.72 M

Question 13
Calculate the percent by mass of potassium nitrate in a solution made from 45.0 g KNO3 and 295 mL of water. Density of water is 0.997 g/mL.
a. 1.51 percent
b. 7.57 percent
c. 13.3 percent
d. 15.2 percent
e. None of the above

Question 14
How many grams of water are needed to dissolve 27.8 g of ammonium nitrate, NH4NO3, in order to prepare a 0.452 m solution?
a. 0.157 g
b. 36.2 g
c. 100 g
d. 769 g
e. 157 g

Question 15
The density of a 20.3 M CH3OH (methanol) solution is 0.858 g/mL. What is the molality of this solution? H2O is the solvent.
a. 17.4 m
b. 20.8 m
c. 23.7 m
d. 70.0 m
e. 97.5 m

Question 16
The solubility of gases in water usually decreases with ________.
a. increasing pressure
b. increasing temperature
c. decreasing temperature

Question 17
What is the freezing point of a solution that contains 10.0 g of glucose (C6H12O6) in 100 g of H2O? Kf for water is 1.86oC/m
a. -0.186oC
b. +0.186oC
c. -0.10oC
d. +0.10oC
e. -1.03oC

Question 18
Which of the following statements describes what happens during osmosis?
a. Pure solvent diffuses through a membrane, but solutes do not.
b. Pure solutes diffuse through a membrane, but solvent does not.
c. Pure solvent and a solution both diffuse at the same time through a membrane.
d. Gases diffuse through a membrane into a solution and build up pressure.

Question 19
A solution that contains 55.0 g of ascorbic acid (Vitamin C) in 250 g of water freezes at -2.34oC. Calculate the molar mass (g/mol) of the solute. Kf of water is 1.86oC/m.
a. 1.26
b. 10.9
c. 43.6
d. 175
e. 277

Question 20
What is the approximate Na+ ion concentration in a 0.75 M Na2CO3 solution?
a. 0.375 M
b. 0.75 M
c. 1.25 M
d. 1.50 M
e. 2.25 M