ch 2
If a volume of nitrous oxide gas at 45.0 °C decreases from 50.0 mL to 25.0 mL, what is the final Celsius temperature? Assume pressure remains constant?
-114 °C
A sample of hydrogen bromide gas occupies 45.5 cm3 at 30.0 °C and 30.0 in. Hg. What is the final Celsius temperature if the volume is 45.5 cm3 at 15.0 in. Hg?
-121 °C
The pressure of a neon gas sample at 25 °C decreases from 1.00 atm to 0.500 atm. What is the final Celsius temperature if the volume remains constant?
-124 °C
The volume of 350. mL of gas at 25°C is decreased to 125 mL at constant pressure. What is the final temperature of the gas?
-167°C
A rare metal alloy is a superconductor at 55 K. What is the temperature on the Celsius scale?
-218 °C
What are the freezing point and boiling point of water on the Celsius scale?
0 °C and 100 °C
If a gas pressure gauge reads 15 mm Hg, what is the pressure in atmospheres?
0.020 atm
A gas occupies 22.4 L at STP and 14.5 L at 100°C and 2.00 atm pressure. How many moles of gas did the system gain or lose?
0.05 moles lost
A balloon filled with 0.500 L of air at sea level is submerged in the water to a depth that produces a pressure of . What is the volume of the balloon at this depth?
0.154 L
A "shielding gas" mixture of argon and carbon dioxide is sometimes used in welding to improve the strength of the weld. If a gas cylinder of this two-part mixture was at 4.0 atm pressure and this mixture was 90.% argon, what would be the pressure due to the carbon dioxide gas component?
0.40 atm
What is the volume of 1.20 x 10^22 molecules of nitric oxide gas, NO, at STP?
0.447 L
Suppose a chemical reaction generated a 50% nitrogen/50% oxygen (by volume) mixture of gas that had a total volume of 22.4 liters at STP. This gas sample is composed of:
0.5 mole of nitrogen and 0.5 mole of oxygen.
The vapor pressure of water at 20.0°C is 17.5 mm Hg . If the pressure of a gas collected over water was measured to be 453.0 mm Hg. What is the pressure of the pure gas?
0.573 atm
What is the final pressure of a system (atm) that has the volume increased from 0.75L to 1.1 L with an initial pressure of 1.25 atm?
0.85
If carbon dioxide gas is collected over water at 60 °C and 1.10 atm, what is the partial pressure of the CO2? The vapor pressure of water at 60 °C is 0.197 atm.
0.90 atm
If each of the following gas samples have the same temperature and pressure, which sample has the greatest volume?
1 gram of H2
A sample of air contains nitrogen at 599 torr, oxygen at 154 torr, argon at 6 torr, and carbon dioxide. Assuming standard pressure, what is the partial pressure of carbon dioxide gas?
1 torr
How many carbon dioxide molecules are in 500.0 mL of CO2 gas at STP?
1.34 x 10^22 molecules
A basketball is inflated to a pressure of 1.50 atm in a 20.0°C garage. What is the pressure of the basketball outside where the temperature is -5.00°C?
1.37 atm
A piece of metal ore weighs 8.25 g. When a student places it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 26.47 mL. What is the density of the ore?
1.58 g/mL
If a mixture of gases contained 78% nitrogen at a pressure of 984 torr and 22% carbon dioxide at 345 torr , what is the total pressure of the system?
1.75 atm
The initial volume of a gas cylinder is 750.0 mL. If the pressure of a gas inside the cylinder changes from 840.0 mm Hg to 360.0 mm Hg, what is the final volume the gas occupies?
1.750 L
What is the volume of 4.80 x 10^22 molecules of nitrous oxide gas, N2O, at STP?
1.79 L
If the partial pressure of carbon dioxide gas in a blood capillary is 45 mm Hg, what is the pressure expressed in inches of mercury?
1.8 in. Hg
What is the volume of 2.75 x 1024 molecules of ammonia gas, NH3, at STP?
102 L
A 75.0 L steel tank at 20.0°C contains acetylene gas, C2H2, at a pressure of 1.39 atm. Assuming ideal behavior, how many grams of acetylene are in the tank?
113 g
A 10.0 mL volume of mercury has a mass of 0.136 kg. What is the density of mercury in grams per milliliter?
13.6 g/mL
Stanley Miller provided evidence for the theory of evolution by simulating Earth's primordial conditions. He excited methane, ammonia, hydrogen, and water vapor in a glass sphere with electricity and UV light. If the partial pressures were 340 torr, 125 torr, 65 torr, and 100 torr, what was the total gas pressure in the glass sphere?
1390 torr
A sample of air at 7.50 atm is heated from 224K to 448K. If the volume remains constant, what is the final pressure?
15.0 atm
A mass of mercury occupies 0.950 L. What volume would an equal mass of ethanol occupy? The density of mercury is and the density of ethanol is 0.789 g/mL.
16.3 L
If a volume of nitric oxide gas at 25.0 °C increases from 2.00 L to 3.00 L, what is the final Celsius temperature? Assume pressure remains constant.
174 °C
The phase diagram of a substance is shown below. The approximate normal melting point of this substance is
190 K.
A 1.00 L flask contains nitrogen gas at 25°C and 1.00 atm pressure. What is the final pressure in the flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to -55°C?
2.01 atm
If 2.50 L of hydrogen gas is collected over water at 40 °C and 767 mm Hg, what is the volume of dry hydrogen gas at STP? The vapor pressure of water at 40 °C is 55.3 mm Hg.
2.04 L
A sample of neon gas at 1.20 atm compresses from 0.250 L to 0.125 L. If the temperature remains constant, what is the final pressure in atm?
2.40 atm
An "empty" aerosol can at 25°C still contains gas at 1.00 atmosphere pressure. If an "empty" can is thrown into a 475°C fire, what is the final pressure in the heated can?
2.51 atm
If a nitrogen gas sample occupies a volume of 2.55 L at 22.0 °C and 0.860 atm, what is the mass of the N2 gas? (R = 0.0821 atm•L/mol•K)
2.54 g
What is the final volume of a gas that initially occupies 2.50 L at 298 K and is subsequently heated to 321K?
2.69 L
If the melting point of vanadium metal is 1910°C, what is its melting point in Kelvin?
2183 K
Osmium is one of the most dense elements (22.5 g/cm3). What is the mass of 10.0cm3 of the metal?
225 g
Determine the volume of an object that has a mass of 455.6 g and a density of 19.3 g/cm3.
23.6 mL
A sample of nitrogen dioxide gas occupies 625 cm3 at 70.0 °C and 15.0 psi. What is the final Celsius temperature if the volume is 545 cm3 at 15.0 psi?
26 °C
The density of aluminum is 2.702 g/cm3. What is the final liquid level of water if 1.130 ounces of aluminum is dropped into a graduated cylinder containing 15.90 mL of water?
27.76 mL
What are the freezing point and boiling point of water on the Kelvin scale?
273 K and 373 K
The freezing point of water on the Kelvin temperature scale is
273 K.
The density of mercury is 13.5 g/mL. What is the mass in kg of mercury that fills a 0.250-L flask?
3.38 kg
What is the pressure of a 1.0 L flask containing of He at 25°C? (R= 0.0821 L atm/ mol K)
3.7 atm
A sample of air at 7.50 atm is cooled from 448K to 224K. If the volume remains constant, what is the final pressure?
3.75 atm
Use the diagram below to answer the following questions. The normal boiling point of this substance is approximately
300°C.
What are the freezing point and boiling point of water on the Fahrenheit scale?
32 °F and 212 °F
A train robber in a western movie steals two gold ingots, each of which has a volume of 1000. cm3. The density of gold is 19.3 g/cm3. What is the mass of the two ingots?
38,600 g
The pressure of an air sample at 190 K increases from 415 mm Hg to 830 mm Hg. What is the final Kelvin temperature if the volume remains constant?
380K
If the pressure of 50.0 mL of oxygen gas at 100 °C increases from 735 mm Hg to 925 mm Hg, what is the final volume? Assume temperature remains constant.
39.7 mL
If the number of moles of a gas initially contained in a 2.10 L vessel is doubled, what is the final volume of the gas in liters? (Assume the pressure and temperature remain constant.)
4.20
A gas sample occupies 3.50 liters of volume at 20.°C. What volume will this gas occupy at 100°C (reported to three significant figures)?
4.46 L
A 5.00 mL volume of methane gas is cooled from 60.0 °C to 30.0 °C. If the pressure remains constant, what is the final volume in milliliters?
4.55 mL
A 5.00 liter balloon of gas at 25°C is cooled to 0°C. What is the new volume (liters) of the balloon?
4.58 liters
A 40.0 mL volume of ethane gas is heated from 25.0 °C to 50.0 °C. If the pressure remains constant, what is the final volume in milliliters?
43.4 mL
A sample of krypton gas at 3.50 atm is heated from 20.0 °C to 150.0 °C. If the volume remains constant, what is the final pressure?
5.05 atm
Magnesium is one of the least dense elements (d = 1.74 g/cm3). What is the volume of a 10.0 g sample of the metal?
5.75 cm3
If 68.0 cm3 of oxygen gas is collected over water at 45 °C and 765 mm Hg, what is the volume of dry oxygen gas at STP? The vapor pressure of water at 45 °C is 71.9mm Hg.
53.2 cm3
If a barometer reads 535 mm Hg, what is the atmospheric pressure expressed in centimeters of mercury?
53.5 cm Hg
If 1.06 mol of helium exert a pressure of 0.750 atm at 210.0 °C, what is the volume in liters? (R = 0.0821 atm•L/mol•K)
56.0 L
Which of the following is the lowest temperature?
57°F
How many xenon atoms are in 10.0 L of Xe gas at STP?
6.02 x 10^24 atoms
What is the value of the gas constant, R, in units of mm Hg*cm^3/mol*K
6.236 × 104
If the pressure of 1.50 L of hydrogen gas at 100 °C decreases from 0.500 atm to 0.115 atm, what is the final volume? Assume temperature remains constant.
6.52 L
A sample of xenon gas at 786 mm Hg is cooled from 100.0 °C to 50.0 °C. If the volume remains constant, what is the final pressure?
681 mm Hg
How many hydrogen molecules are in 2.75 L of H2 gas at STP?
7.39 x 10^22 molecules
Divers often inflate heavy duty balloons attached to salvage items on the sea floor. If a balloon is filled to a volume of at a pressure of , what is the volume of the balloon when it reaches the surface?
7.50 L
A sample of air is composed of nitrogen, oxygen, and argon gases. If the partial pressure of nitrogen is 587 mm Hg, oxygen is 158 mm Hg, and argon is 7 mm Hg, what is the total pressure?
752 mm Hg
What is the equivalent pressure of 760 torr in units of mm Hg?
760
Which of the following does not express standard atmospheric pressure?
760 cm Hg
What is the vapor pressure of water at 100 °C?
760 mm Hg
A sample of 0.255 mole of gas has a volume of 748 mL at 28°C. Calculate the pressure of this gas. (R= 0.0821 L ∙ atm / mol ∙ K)
8.42 atm
A block of copper has a mass of 143.584 g and measures 5.05 cm by 2.55 cm by 1.25 cm. What is the density of the rectangular copper block?
8.92 g/cm3
Determine the mass of an object that has a volume of 88.6 mL and a density of 9.77 g/mL.
866 g
Liquid argon boils at -186 °C. What is the boiling point on the Kelvin scale?
87 K
A rigid cylinder contains 2.00 liters of gas at a temperature of 25°C. If the pressure of this gas is changed from 0.500 atmospheres to 1.50 atmospheres, what will be the new temperature (in Kelvin, reported to three significant figures) of the gas? (The volume is constant.)
894 K
How many moles of gas were added to a balloon that started with 2.3 moles of gas and a volume of 1.4 L given that the final volume was 7.2L?
9.5
How many moles of gas were added to a balloon that started with 2.3 moles of gas and a volume of 1.4L given that the final volume was 7.2L?
9.5
The outside temperature is 35°C, what is the temperature in °F?
95°F
Assign the appropriate labels to the phase diagram shown below.
A = gas, B = solid, C = liquid, D = triple point
According to the conservation of mass and energy law, which of the following is true of an atomic fission bomb?
A small amount of mass is converted into energy.
Which of following statements are consistent with the Kinetic Molecular Theory?
All of the above statements are consistent with the Kinetic Molecular Theory.
A 3.76 g sample of a noble gas is stored in a 2.00 L vessel at 874 torr and 25°C. What is the noble gas?(R= 0.0821 L atm/ mol K)
Ar
What principle states that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules?
Avogadro's theory
The volume of a gas is inversely proportional to the pressure of a gas is known as
Boyle's Law
Use the diagram below to answer the following questions. Melting occurs along the
CB line.
What is the term for the base unit of temperature in the metric system?
Celsius degree (°C)
The volume of a gas is proportional to the temperature of a gas is known as
Charles's Law
What is the term for the base unit of temperature in the English system?
Fahrenheit degree (°F)
Which assumption of Kinetic Molecular Theory is not followed when a real gas shows non-ideal behavior?
Gas molecules move at random with no attractive forces between them.
Which of the following represents the graph of pressure versus volume for a gas at constant temperature?
Graph (a)
Which of the following represents the graph of kinetic energy versus the Kelvin temperature for an ideal gas?
Graph (d)
Which of the following represents the graph of volume versus Kelvin temperature for a gas at constant pressure?
Graph (d)
What is the term for the base unit of temperature in the SI system?
Kelvin unit (K)
Which of the following statements about energy is FALSE?
Kinetic energy is the energy associated with its position or composition.
Which of the following is an observed property of liquids?
Liquids that are soluble mix homogeneously.
Which of the following diatomic elements would have a mass of 19.08 grams stored in a 3.82L container at 3,632 mm Hg and 100°C? (R= 0.0821 L atm/ mol K)
O2
Which of the following is an observed property of solids?
Solids can have noncrystalline structures.
All of the following statements are consistent with the kinetic molecular theory of gases EXCEPT:
Strong attractive forces hold the gas molecules together.
Which one of the following statements about temperature scales is false?
The Celsius degree is smaller than the Fahrenheit degree.
A certain volume of gas was confined in a rigid container. If the pressure of the gas sample in the container was doubled, what happened to the temperature?
The Kelvin temperature doubled.
Which of the following is NOT part of the Kinetic Molecular Theory?
The average energy of the particles is dependent on the molecular mass of the particle.
Which of the following explains why the pressure of a gas decreases when the temperature decreases, and the volume remains constant?
The collision frequency decreases.
Gas density can be calculated by dividing the mass of gas by its volume. If you took a balloon of gas and then warmed the balloon in a sunny window, what can now be said about the density of the gas in the balloon?
The gas density will decrease.
According to Boyle's law, what happens to a gas as the volume increases?
The pressure decreases.
What happens to the pressure of a gas if the number of molecules increases twofold (volume and temperature remain constant)?
The pressure increases twofold.
According to Gay-Lussac's law, what happens to a gas as temperature increases?
The pressure increases.
One liter of a gas is in a sealed chamber containing a moveable piston. If the piston is moved so that the volume of the gas is compressed to a volume of one-half liter, what will happen to the pressure on the gas? (Assume the temperature is constant and no gas particles are lost.)
The pressure will be twice the original value.
Consider the phase diagram shown. Choose the statement below that is TRUE.
The solid phase of this substance is higher in density than the liquid phase.
Identify triple point.
The temperature and pressure where liquid, solid, and gas are equally stable and are in equilibrium.
Which of the assumptions of the kinetic-molecular theory best explains the observation that a balloon collapses when exposed to liquid nitrogen (which is much colder than a cold winter day!!)?
The velocity of gas molecules is proportional to their Kelvin temperature.
What happens to the volume of a gas when you double the number of moles of gas while keeping the temperature and pressure constant?
The volume doubles
What happens to the volume of a gas if the number of molecules increases twofold (pressure and temperature remain constant)?
The volume increases twofold.
According to Charles's law, what happens to a gas as temperature increases?
The volume increases.
Boyle's Law is expressed as:
V is proportional to 1/P
Avogadro's Law is expressed as:
V is proportional to n
An approximation of absolute zero was made from an extrapolation of
V vs. T
To solve problems using Charles's Law, which mathematical equation should be used?
V1/T1=V2/T2
To solve problems using Avogadro's Law, which mathematical equation should be used?
V1/n1=v2/n2
At the same temperature, which of the following noble gases contains atoms with the slowest average velocity?
Xe
The freezing point of methane is -295°F and the boiling point is -263°F. The temperature of the surface of Titan, a moon of Saturn, is 93 K. If methane exists on Titan, it is
a liquid.
A fuel cell contains hydrogen and oxygen gas. The gases react explosively and the energy converts water to steam. The steam drives a turbine which turns a generator to produce electricity. What changes are involved in the process?
all of the above
What is the temperature at which an ideal gas exerts zero pressure?
all of the above
Which of the following describes a substance in the gaseous physical state?
all of the above
Which of the following describes a substance in the liquid physical state?
all of the above
Which of the following describes a substance in the solid physical state?
all of the above
Which of the following expresses standard atmospheric pressure?
all of the above
Which of the following gases occupies 22.4 L at STP?
all of the above
Which of the following is a form of energy?
all of the above
Which of the following is an observed property of gases?
all of the above
Which of the following gas law relationships is true?
all of the above are true
Gaseous mixtures ________.
are all homogeneous
What is the third most abundant component of dry air?
argon
The nighttime and daytime temperatures on Mercury are 13 K and 683 K respectively. The melting point and boiling point of sulfur is 246°F and 832°F. Which of the following statements is true? On Mercury sulfur exists
as both a liquid and a solid.
What is the term for the temperature at which the vapor pressure of a liquid is equal to the atmospheric pressure?
boiling point
A nuclear power plant uses plutonium-239 to convert water to steam. The steam drives a turbine which turns a generator to produce electricity. Which is not a form of energy in this process?
chemical energy
A fuel cell contains hydrogen and oxygen gas. The gases react explosively and the energy converts water to steam. The steam drives a turbine which turns a generator to produce electricity. What two forms of energy are represented by the fuel cell and the steam?
chemical energy and heat energy
A fuel cell contains hydrogen and oxygen gas. The gases react explosively and the energy converts water to steam. The steam drives a turbine which turns a generator to produce electricity. What two forms of energy are represented by the fuel cell and the turbine?
chemical energy and mechanical energy
What is the term for a change of state from a gas to a liquid?
condensation
What is the term for a direct change of state from a gas to a solid?
deposition
What is the term that describes the relationship between two variables such that when one variable doubles, the other variable doubles?
directly proportional
What is the term for gas molecules colliding with no change in total energy?
elastic collision
Pressure is defined as
force divided by unit area.
Consider the phase diagram below. If the dashed line at 1 atm of pressure is followed from 100 to 500 °C, what phase changes will occur (in order of increasing temperature)?
fusion, followed by vaporization
Predict the physical state of ammonia at -15 °C (Mp = -77 °C, Bp = -33 °C) and normal atmospheric pressure.
gas
The phase diagram of a substance is shown below. What is the physical phase of the substance at T = 400 K and P = 2.0 atm?
gas
Which physical state demonstrates unrestricted movement of particles?
gaseous state
Which physical state demonstrates very high kinetic energy?
gaseous state
Which of the following is not an observed property of gases?
gases compress infinitely
In comparing gases with liquids, gases have ________ compressibility and ________ density.
greater; smaller
What is the term for global warming that results from trapping heat energy by gas molecules in the upper atmosphere?
greenhouse effect
If 0.50 mole H2(g) and 1.0 mole He(g) are compared at standard temperature and pressure, the two gases will:
have equal average molecular kinetic energies
When a cannonball is shot from a cannon, at what point in its flight is the kinetic energy of the cannonball at a maximum?
in flight near the ground
Which of the following decreases the pressure of a gas?
increasing the volume
The energy of molecules of a gas:
is distributed over a wide range at constant temperature
If the number of moles of gas is doubled at constant temperature and volume, the pressure of the gas
is doubled.
Use the diagram below to answer the following questions. According to the diagram, the solid phase of this substance
is more dense than the liquid phase.
What is the term for the energy of a particle that is related to mass and velocity?
kinetic energy
What is the term that describes gas molecules demonstrating ideal behavior?
kinetic theory
Which of the following laws states that energy cannot be created or destroyed?
law of conservation of energy
Predict the physical state of argon at -187 °C (Mp = -189 °C, Bp = -186 °C) and normal atmospheric pressure.
liquid
Predict the physical state of krypton at -155 °C (Mp = -157 °C, Bp = -152 °C) and normal atmospheric pressure.
liquid
The phase diagram of a substance is shown below. What is the physical phase of the substance at T = 225 K and P = 1.1 atm?
liquid
What is the term for a change of state from a solid to a liquid?
melting
What is the major component of the air we breathe?
nitrogen
Which of the following gases is an example of an ideal gas?
none of the above
Which of the following is true according to the kinetic theory of gases?
none of the above
A nuclear power plant uses uranium-235 to convert water to steam. The steam drives a turbine which turns a generator to produce electricity. What are the initial and final forms of energy in this process?
nuclear energy and electrical energy
A nuclear power plant uses radioactive uranium to convert water to steam. The steam drives a turbine which turns a generator to produce electricity. What two forms of energy are represented by the uranium and the steam?
nuclear energy and heat energy
A glass cylinder contains four liquid layers: mercury (d = 13.6 g/mL), chloroform (d = 1.49 g/mL), water (d = 1.00 g/mL), ether (d = 0.708 g/mL). If a gold nugget (d=19.3 g/mL) is dropped into the cylinder, where does it come to rest?
on the bottom of the cylinder
A glass cylinder contains four liquid layers: mercury (d = 13.6 g/mL), chloroform (d = 1.49 g/mL), water (d = 1.00 g/mL), ether (d = 0.708 g/mL). If a rubber stopper (d = 1.2 g/mL) is dropped into the cylinder, where does it come to rest?
on top of the chloroform layer
Use the diagram below to answer the following questions. What phases can be present at 200°C and 0.75 atm pressure?
only the liquid phase
At the same temperature, which of the following gases contains molecules with the slowest average velocity?
ozone, O3
Define vapor pressure.
partial pressure of water in a gaseous mixture
Energy that is associated with the position or composition of an object is called
potential energy
Predict the physical state of ammonia at -95 °C (Mp = -77 °C, Bp = -33 °C) and normal atmospheric pressure.
solid
Predict the physical state of krypton at -175 °C (Mp = -157 °C, Bp = -152 °C) and normal atmospheric pressure.
solid
The phase diagram of a substance is shown below. What is the physical phase of the substance at T = 100 K and P = 0.1 atm?
solid
Which physical state demonstrates very low kinetic energy?
solid state
Use the diagram below to answer the following questions. What phase changes occur when the pressure is held constant at 0.25 atm and the temperature increases from 100°C to 300°C?
solid → gas
When temperature-volume measurements are made on 1.0 mol of gas at 1.0 atm, a plot V versus T results in a
straight line.
What is the term for a direct change of state from a solid to a gas?
sublimation
A barometer uses mercury because:
the density of mercury is very large which allows the barometer to be short.
What is the term for a change of state from a liquid to a gas?
vaporizing
