Multiple
Choice
Identify the letter of the choice that best completes the statement or answers the
question.
|
|
|
1.
|
Which of the following
relationships are true for gases?
1. The volume of a gas is directly proportional to its pressure in mm
Hg.
2. The
pressure of a gas in inversely proportional to its temperature in kelvin.
3. The moles of a gas are directly
proportional to the gas constant R. a. | 1 only | b. | 2 only | c. | 3 only | d. | 2 and 3 | e. | none are true | | |
|
|
|
2.
|
What volume is occupied by 5.00
g CH4 at STP (standard temperature and pressure)? (R = 0.08206
L·atm/mol·K) a. | 3.29 L | b. | 6.99 L | c. | 7.62 L | d. | 22.4 L | e. | 112 L | | |
|
|
|
3.
|
Hydrochloric acid reacts with
zinc to produce hydrogen gas according to the reaction below.
2 HCl(aq) + Zn(s) → ZnCl2(aq) + H2(g)
If 500.0 mL of 0.200 M HCl is combined
with 3.68 g Zn, what volume of hydrogen gas can be produced? Assume the temperature and pressure of
the gas are 25°C and 747 mm Hg, respectively. (R = 0.08206
L·atm/mol·K) a. | 0.0562 L | b. | 0.101 L | c. | 1.24 L | d. | 1.40 L | e. | 16.7 L | | |
|
|
|
4.
|
A 1.00 L flask at 298 K
contains a mixture of He and O2 with a total pressure of 1.00 atm. If the mole fraction of
O2 is 0.50, what is the mass fraction of O2? a. | 0.11 | b. | 0.32 | c. | 0.37 | d. | 0.50 | e. | 0.89 | | |
|
|
|
5.
|
An unknown gaseous hydrocarbon
contains 85.63 % C. Its density equals 0.488 g/L at 0.355 atm and 373 K. What is the molecular
formula of the gas? (R = 0.08206 L·atm/mol·K) a. | C2H4 | b. | C3H6 | c. | C4H8 | d. | C5H10 | e. | C6H12 | | |
|
|
|
6.
|
At 298 K, the average velocity
of a hydrogen molecule is 1.92 × 103 m/s. What is the average
velocity of a chlorine molecule (Cl2) at the same temperature? a. | 1.55 m/s | b. | 54.6 m/s | c. | 98.4 m/s | d. | 324 m/s | e. | 821 m/s | | |
|
|
|
7.
|
The average velocity of a gas
molecule is a. | inversely proportional to its kinetic
energy. | b. | proportional to the gas constant, R. | c. | inversely proportional to the square root of its mass. | d. | directly proportional to the square of its temperature
inºC. | e. | inversely proportional to the square of its temperature in
K. | | |
|
|
|
8.
|
One way in which real gases
differ from ideal gases is that the molecules of a real gas a. | have no kinetic energy. | b. | occupy no
volume. | c. | are attracted to each other. | d. | have positive and negative spins. | e. | are always polar. | | |
|
|
|
9.
|
Which of the following
statements concerning intermolecular forces are correct?
1. London dispersion forces exist in all
molecular solids.
2. London dispersion forces increase as the number of electrons
increases.
3.
Dipole-dipole attractions occur in nonpolar molecules if they have polar
bonds.
4.
Hydrogen bonding only occurs for molecules containing OH bonds. a. | 1 only | b. | 1 and 2 | c. | 4 only | d. | 1, 2, and 4 | e. | 2 and 3 | | |
|
|
|
10.
|
High surface tension in liquids
is an indication of a. | strong adhesive
forces. | b. | no adhesive forces. | c. | strong intermolecular forces. | d. | strong intramolecular bonds. | e. | π-bonding. | | |
|
|
|
11.
|
Which process requires the
greatest exothermic change in enthalpy for water? a. | vaporization | b. | condensation | c. | sublimation | d. | melting | e. | fusion | | |
|
|
|
12.
|
Diethyl ether has an enthalpy
of vaporization of 29.0 kJ/mol. The compound has a vapor pressure of 524 mm Hg at 298 K. At what
temperature is the vapor pressure equal to 7.60 ×
102 mm Hg? (R = 8.314 J/K·mol) a. | 308 K | b. | 321 K | c. | 372 K | d. | 518 K | e. | 721 K | | |
|
|
|
13.
|
An atom located on a lattice
point is shared equally between ________ unit cells.
|
|
|
14.
|
The mass of a unit cell of
sodium is 7.635 × 10-23 g. How many atoms are
contained in a unit cell?
|
|
|
15.
|
What is the definition of
molality? a. | moles of solute per liter of solution | b. | grams of solute per kg of solution | c. | grams of solute per kg of solvent | d. | moles of solute per kg of solvent | e. | moles of solute per liter of solvent | | |
|
|
|
16.
|
To prepare approximately 1
liter of a solution that is 4.75% by mass NaCl, one should a. | dissolve 4.75 g NaCl in water up to a total volume of 1.00
L. | b. | dissolve 47.5 g NaCl in 1.00 ×
103 g water. | c. | dissolve 47.5 g NaCl in 952.5 g
water. | d. | dissolve 952.5 g NaCl in 47.5 g water. | e. | dissolve 46.5 g NaCl in 1.00 kg water. | | |
|
|
|
17.
|
What is the molality of a
13.82% by mass glucose solution? The molar mass of C6H12O6 is 180.16
g/mol. a. | 0.1604 m | b. | 0.7671 m | c. | 0.8901 m | d. | 4.529 m | e. | 28.90 m | | |
|
|
|
18.
|
What is the mole fraction of
KBr present in a solution that is 11.04% by mass aqueous KBr? The molar mass of KBr is 119.0
g/mol. a. | 0.01845 | b. | 0.05832 | c. | 0.1241 | d. | 0.2719 | e. | 1.042 | | |
|
|
|
19.
|
Concentrated NaOH is 19.3 M and
has a density of 1.53 g/mL. What is the percent NaOH by mass of concentrated NaOH? a. | 11.8% | b. | 37.0% | c. | 49.5% | d. | 50.5% | e. | 77.2% | | |
|
|
|
20.
|
What is a primary factor for
the low solubility of AgCl(s) in water? a. | The lattice energy of AgCl is greater than
the enthalpy of hydration for the ions. | b. | The enthalpy of hydration for
Cl- is very exothermic. | c. | The enthalpy of hydration for
Ag+ is endothermic. | d. | The heat of solution of AgCl is
exothermic. | e. | Small ions, such as Cl-, have a positive enthalpy of
hydration. | | |
|
|
|
21.
|
The Henry's law constant for
N2 in water at 25°C is 8.4 ×
10-7 M/mm Hg. What is the equilibrium concentration of N2 in water when the
partial pressure of N2 is 653 mm Hg? a. | 1.3 ×
10-9 M | b. | 7.2 ×
10-7 M | c. | 5.5 ×
10-4 M | d. | 3.1 ×
10-2 M | e. | 7.8 ×
108 M | | |
|
|
|
22.
|
The vapor pressure of pure
water at 35ºC is 42.2 mm Hg. What is the vapor pressure of a mixture of 15 g sucrose
(C12H22O11, molar mass 342.3 g/mol) and 85 g water? a. | 7.45 mm Hg | b. | 21.8 mm Hg | c. | 35.9 mm Hg | d. | 40.6 mm Hg | e. | 41.8 mm Hg | | |
|
|
|
23.
|
The freezing point depression
constant for water is -1.86ºC/m. If 2.00 g Na2SO4 is dissolved in
18.0 g H2O, the freezing point is lowered by -3.82ºC. Calculate the van't Hoff
factor for Na2SO4. a. | 1.53 | b. | 2.01 | c. | 2.41 | d. | 2.63 | e. | 3.00 | | |
|
|
|
24.
|
What is the osmotic pressure of
0.250 M aqueous urea (CON2H4) at 25ºC? (R = 0.08206
L·atm/mol·K) a. | 0.295 atm | b. | 0.513 atm | c. | 2.50 atm | d. | 6.11 atm | e. | 97.8 atm | | |
|
|
|
25.
|
A(n) ________ is a colloidal
dispersion of a liquid in another liquid. a. | sol | b. | gel | c. | surfactant | d. | hypotonic | e. | emulsion | | |
|
Completion
Complete each sentence or statement.
|
|
|
26.
|
Boyle learned that at constant
temperature and number of molecules, the pressure of a gas is inversely proportional to its
________.
|
|
|
27.
|
At a constant pressure and
number of molecules, the volume of a gas is directly proportional to its temperature. This
relationship is known as ________ law.
|
|
|
28.
|
The average kinetic energy of a
gas molecule depends only on its ________.
|
|
|
29.
|
A solution in which there is
more dissolved solute than in a saturated solution is known as a(n) ________ solution.
|
Essay
|
|
|
30.
|
The pressure exerted by gas
molecules on the inside of a container is due to gas molecules colliding with the walls of the
container. Why does 1 mole of oxygen molecules apply the same pressure to the inside of a flask as 1
mole of hydrogen molecules, even though the oxygen has sixteen times the mass?
|
|
|
31.
|
What are two ways in which real
gases differ from ideal gases?
|
|
|
32.
|
Hydrogen halides behave as
strong acids, with the exception of HF. Use intermolecular forces to explain why HF is a weak
acid.
|
|
|
33.
|
Two important allotropes of
phosphorus are white phosphorus and red phosphorus. White phosphorus, P4, has a melting
point of 44.1ºC and spontaneously reacts with oxygen. Red phosphorus, P, melts at 280ºC
and is stable in air. Use your knowledge of intermolecular and intramolecular bonds to explain why
these two forms of the same element have such different properties.
|