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WorksheetsU6 Gas Laws Practice Exam
Total questions: 38
Worksheet time: 32mins
When a quantity of electricity is converted to heat, the heat energy produced is measured in
amperes
joules
volts
degrees
As ice melts at standard pressure, its temperature remains at 0°C until it has completely melted. Its potential energy
decreases
increases
remains the same
At which temperature would the molecules in a one gram sample of water have the lowest average kinetic energy?
10 K
5°C
-100°C
5 K
In which flask do the molecules of H2O have the greatest average kinetic energy?
1
2
3
4
Two samples of gold that have different temperatures are placed in contact with one another. Heat will flow spontaneously from a sample of gold at 60°C to a sample of gold that has a temperature of
80°C
70°C
50°C
60°C
What is the equivalent of 0 Kelvin on the Celsius scale?
-100°
-273°
100°
273°
Which graph best shows the relationship between Kelvin temperature and average kinetic energy?
A
B
C
D
The temperature of a substance is a measure of its particles
average potential energy
specific heat
average kinetic energy
total energy
Which Kelvin temperature is equal to -73°C?
346 K
200 K
173 K
100 K
As ice at 0°C changes to water at 0°C, the average kinetic energy of the ice molecules
decreases
increases
remains the same
Which change of phase is exothermic?
CO₂(s) → CO₂(g)
H₂O(g) → H₂O(s)
NaCl(s) → NaCl(l)
H₂O(s) → H₂O(g)
Which substance has vibrating particles in regular, fixed positions?
Ca(s)
Hg(l)
CaCl₂(l)
Cl₂(g)
Two basic properties of the gas phase are
a definite shape but no definite volume
no definite shape and no definite volume
no definite shape but a definite volume
a definite shape and a definite volume
Which 5.0-milliliter sample of NH₃ will take the shape of and completely fill a closed 100.0-milliliter container?
NH₃(aq)
NH₃(l)
NH₃(g)
NH₃(s)
Which graph shows the pressure-temperature relationship expected for an ideal gas?
Graph A
Graph B
Graph C
Graph D
Under which conditions does a real gas behave most like an ideal gas?
at high temperatures and high pressures
at high temperatures and low pressures
at low temperatures and low pressures
at low temperatures and high pressures
One reason that a real gas deviates from an ideal gas is that the molecules of the real gas have
a short-range motion
no net loss of energy on collision
forces of attraction for each other
a negligible volume
Which of the following gases behaves most like an ideal gas?
CO₂(g)
NH₃(g)
O₂(g)
H₂(g)
Each stoppered flask below contains 2 liters of a gas at STP. Each gas sample has the same
mass
number of atoms
number of molecules
density
The temperature of 15 grams of water is increased by 3.0 Celsius degrees. How much heat was absorbed by the water?
189 J
21 J
50 J
76 J
Under which conditions will the volume of a given sample of a gas decrease?
increased pressure and decreased temperature
decreased pressure and decreased temperature
increased pressure and increased temperature
decreased pressure and increased temperature
Which graph represents the relationship between volume and Kelvin temperature for an ideal gas at constant pressure?
Graph A
Graph B
Graph C
Graph D
The volume of a 1.00-mole sample of an ideal gas will decrease when the
A) pressure decreases and the temperature increases
B) pressure increases and the temperature increases
C) pressure decreases and the temperature decreases
D) pressure increases and the temperature decreases
A sample of oxygen gas has a volume of 150. milliliters at 300 K. If the pressure of the sample is held constant and the temperature is raised to 600 K, the new volume of the sample will be
A) 150. ml
B) 600. ml
C) 300. ml
D) 75.0 ml
When 7.00 moles of gas A and 3.00 moles of gas B are combined, the total pressure exerted by the gas mixture is 76.0 kPa. What is the partial pressure exerted by gas A in this mixture?
A) 22.8 kPa
B) 53.2 kPa
C) 76.0 kPa
D) 76.0 kPa
Gas samples A, B, and C are contained in a system at STP. The partial pressure of sample A is 38.0 kPa and the partial pressure of sample B is 19.0 kPa. What is the partial pressure of sample C?
A) 44.3 kPa
B) 633.3 kPa
C) 19.0 kPa
D) 380.0 kPa
What is the total number of kilojoules of heat needed to change 150. grams of ice to water at 0°C?
A) 50.1 kJ
B) 22.2 kJ
C) 184 kJ
D) 484 kJ
The strongest intermolecular forces of attraction exist in a liquid whose heat of vaporization is
A) 100 J/g
B) 200 J/g
C) 300 J/g
D) 400 J/g
The graph below represents the relationship between temperature and time as heat is added uniformly to a substance, starting when the substance is a solid below its melting point. Which portions of the graph represent times when heat is absorbed and potential energy increases while kinetic energy remains constant?
A) B and D
B) A and C
C) C and D
D) A and B
At 1 atmosphere of pressure, 250.0 grams of a compound at its normal boiling point is converted to a gas by the addition of 34,400 Joules. What is the heat of vaporization for this compound, in Joules per gram?
A) 250.0 J/g
B) 344.00 J/g
C) 2,260 J/g
D) 1376 J/g
A student observing the behavior of paradichlorobenzene first heats 10 grams of the substance in a hot water bath until it is completely liquefied. The following data are recorded as paradichlorobenzene cools. [Data Table Placeholder] What is the freezing point of paradichlorobenzene?
53°C
55°C
58°C
42°C
The graph below represents the uniform heating of a substance, starting with the substance as a solid below its melting point. [Graph Placeholder] Which segment of the graph represents a time when both the solid and liquid phases are present?
AB
BC
DE
EF
The graph below represents the vapor curves of four liquids. [Vapor Curve Graph Placeholder] Which liquid has the highest normal boiling point?
A
B
C
D
Base your answers to questions 34 through 36 on the graph below, which shows the vapor pressure curves for liquids A and B. Which liquid will evaporate more rapidly? Explain your answer in terms of intermolecular forces.
What is the vapor pressure of liquid A at 70°C? Your answer must include correct units.
At what temperature does liquid B have the same vapor pressure as liquid A at 70°C? Your answer must include correct units.
In terms of energy flow, explain why the temperature of the water in the calorimeter increases.
Air bags are an important safety feature in modern automobiles. An air bag is inflated in milliseconds by the explosive decomposition of NaN₃(s). The decomposition reaction produces N₂(g) as well as Na(s), according to the unbalanced equation below. NaN₃(s) → Na(s) + N₂(g) When the air bag inflates, the nitrogen gas is at a pressure of 1.30 atmospheres, a temperature of 301 K, and has a volume of 40.0 liters. Calculate the volume of the nitrogen gas at STP. Your response must include both a correct numerical setup and the calculated volume.
