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Chapter 6-States of Matter: Gases, Liquids, and Solids
The Gaseous State
A gas is one of the four phases of matter (plasma, gases, liquids, solids). In the chemistry, a
phase is a distinct state of a that can been seen that have relatively uniform chemical composition and
physical properties (i.e. density, structure). The most familiar examples of phases are solids, liquids,
and gases. Less familiar phases include plasmas found at very high temperature as in a star.
Gases are, like liquids, fluids: they have the ability to flow and do not resist deformation. Unlike
liquids, however, unconstrained gases do not occupy a fixed volume, but instead expand to fill whatever
space they occupy.
Ideal Gas Concept
An ideal gas is defined to be a system in which there are no intermolecular/interatomic forces (hydrogen
bonding, dipole-dipole attraction, Londodn dispersion forces. Such a system can only exist as a gas. Any
real system will approach ideal gas behavior in the limit that the pressure is extremely low and the
temperature is high enough to overcome attractive intermolecular forces.
Measurement of Gases
Following measurements are used to characterize properties of a gas:
Volume(V): Gases takes up the volume of the container they occupy. Unit of volume is liter(L).
Pressure(P): Gases exert a pressure on the walls of the container because of the collision of molecules
with the wall. Unit of pressure is mm Hg (torr) or atm.
1 atm =760 mm Hg or torr.
Since the mercury barometer was the first one invented, atmospheric pressure is
often expressed in terms of the height of the mercury in the tube above the
mercury in the dish. At sea level, this height averages about 30 inches (760
millimeters). At 10,000 feet (3,000 meters) above sea level, the height would be
only about 20 1/2 inches (520 millimeters). At 20,000 feet (6,000 meters), it
would be about 133/4 inches (350 millimeters); and at 30,000 feet (9,000
meters), about 9 inches (226 millimeters). The changes in atmospheric pressure
caused by the weather are much smaller. At sea level weather changes will
cause the air pressure to change only within the range of about 27 to 31 inches
(686 to 787 millimeters) of mercury.
Using a glass column filled with mercury and inverting it in a pool of
mercury Torricelli made the first barometer to measure atmospheric pressure. What units are
used to measure pressure? How many torr of pressure is equal to 1.55 atm?
Pressure of gases is measured in torr and atm. Torr is the units of pressure obtained using a
Torricellian Barometer shown below. Normally the Height of column is 760 mm Hg. Which is equal to
760 torr Atmospheric Pressure is 760 torr. Other unit related to atmospheric pressure is atm.
1 atm = 760 torr.
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Problem: Convert: a) 10.0 torr to atm. B) 61.0 cm Hg to atm c) 2.75 mm Hg to atm.
Answer:
1 atm
-2
a. 10.0 torr x
= 1.32 x 10 atm
760 torr
10 mm Hg
1 atm
x
= 0.803 atm
1 cm Hg
760 mm Hg
b. 61.0 cm Hg x
1 atm
= 0.362 atm
760 mm Hg
Temperature (T): Gaseous state exists normally at higher temperatures compared to liquid and solid
states. Unit of temperature is Kelvin (K).
Amount(n): Since gases have a mass and a volume, they are considered as matter. The amount of a gas
is measured in moles.
Pure dry air at sea level contains the following components:
c. 2.75 mm Hg x
Oxygen...................... 20.94 %
Nitrogen..............…... 78.09 %
Argon........................ 0.94%
Carbon Dioxide......... 0.03%
Atmospheric Stratification
Although the pressure of the atmosphere decreases more or less uniformly with altitude, the
temperature does not; the temperature gradient undergoes three reversals that divide the atmosphere into
four major sections:
Lower Atmosphere
a) Troposphere (bottom): close to earth.
b) Stratosphere: most atmospheric ozone is concentrated in a layer in the stratosphere.
Upper Atmosphere
c) Mesosphere
d) Thermosphere (top)
Ozone Depletion
However, even the small amount of ozone plays a key role in the atmosphere. The ozone layer
absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface. Most
importantly, it absorbs the portion of ultraviolet light called UVB(UltraViolet-B). UVB is particularly
effective at damaging DNA. It is a cause of melanoma and other types of skin cancer. UVB has been
linked to many harmful effects, including various types of skin cancer, cataracts, and harm to some
crops, certain materials, and some forms of marine life. UVB is particularly effective at damaging DNA.
It is a cause of melanoma and other types of skin cancer.
Boyle's Law
In the mid 1600's, Robert Boyle studied the relationship between the pressure p and the volume
V of a confined gas held at a constant temperature. Boyle observed that the product of the pressure and
volume are observed to be nearly constant. The product of pressure and volume is exactly a constant for
an ideal gas. Volume of a gas is inversely proportional to its pressure.
Mathematically put: V α 1/P , V = k 1/P
V i/V = Pf/Pi
or
P1V1 = P2V2
f
Problem: If a gas has initial pressure 1.0, final volume 0.30 L of volume, and 0.50 atm of final
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pressure what is its initial volume?
Answer:
V i/V = Pf/Pi
f
Vi =
Pf Vf
Pi
Vi =
(0.50 atm)(0.30 L)
= 0.15 L
1.0 atm
Charles's Law
At constant n and P, the volume of a gas increases proportionately as its absolute temperature increases.
If the absolute temperature is doubled, the volume is doubled. Volume is directly proportional to
temperature
Mathematically put:
V α T;
V = kT
V1/T1 = V2/T2
Problem: If 3.00 L of gas at 25˚C is heated to 564 K what would be the final volume of the gas?
Initial temperature: 25˚C + 273 = 298 K;
Final temperature = 546 K; initial volume = 3.00 L.
Vi Vf
=
Ti Tf
Vf =
Vi Tf
Ti
Vf =
(3.00 L)(546 K)
= 5.50 L
298 K
Combined Gas Law
Boyles and Charles Laws were combined to an equation:
Pi Vi Pf Vf
=
Ti
Tf
Pi Vi Tf = Pf Vf Ti
Pf Vf Ti
Pi Vi
Problem: P = 1.00 atm
i
V = 2.30 L
i
T = 25˚C
i
Answer:
PVT
Vf = i i f
Pf Ti
Tf =
P = 0.800 atm
f
V =?L
f
T = 20˚C
f
and substituting:
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(1.00 atm)(2.50 L)(20°C + 273)
(0.800 atm)(25°C + 273)
(1.00 atm)(2.50 L)(293 K)
Vf =
= 3.07 L
(0.800 atm)(289 K)
Vf =
Avogadro's Law
Volume of a gas is directly proportional to moles of gas at constant T and P.
Mathematically put:
V α n;
V = kn;
n = moles of gas
Problem: A gas sample at certain pressure contains 0.25 moles of H2 and has 1.00 L of volume. More
H2 gas were added while maintaining the same pressure and final volume increased to 3.00 L.
How many moles of H2 were added?
Answer: Begin by assuming that V is 1.0 L. Consequently, V must be 3.0 L.
i
f
Vi Vf
=
ni nf
nf =
Vf n i
Vi
nf =
(3.0 L)(0.25 mol H 2 )
= 0.75 mol H 2
1.0 L
Standard Temperature and Pressure (STP).
A common set of conditions that is often used by scientists is called Standard Temperature and Pressure
or STP. When the STP condition is implied, scientists know that the gas must be at a specific
temperature( 273 °C) and a specific pressure(1 atm atmosphere)
Molar Volume a Gas
The molar volume of any gas at STP (( 273 °C) and 1 atm) is 22.4 L.
What volume will 32.0 g of O2 occupy at STP?
32.0 g O2 m.w.(O2) = 32.00 g/mole
n = 1 mole O2 STP means 22.4 L. You could calculate using Ideal Gas Law.
T = 273.15;
pressure is 1 atm
0.0821 L ⋅ atm
Assume P = 1 atm and
K ⋅ mol
Since V, P, T and n involved the equation is:
PV = nRT
(1 mol O 2 )(0.0821 L ⋅ atm/K ⋅ mol)(273 .5K)
V=
= 22.4 L
1.0 atm
V = 22.4 Liters
Note: these calculations verify the molar volume at STP.
R=
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Gas Densities
The density (d) of a gas can be determined from P (pressure), M (molar mass), ideal gas constant (R)
and Kelvin temperature (T) according to the following:
The Ideal Gas Law
An ideal gas can be characterized by three state variables: absolute pressure (P), volume (V), and
absolute temperature (T).
PV=nRT
n = number of moles
R = Uiversal gas constant = 0.08206 L atm/mol = 62.4 L torr/mol K
Problem: What would be the pressure (in atm) of 4.80 g of H2 at 25 C if it has a volume of 20.0 L?
PV = nRT
Answer:
nRT
P =
Solving for pressure, P,
V
P=
nRT
V
n = 4.80 g H 2 x
R=
(1 mol H 2 )
= 2.38 mol H 2
2.02 g H 2
0.0821 L ⋅ atm
K ⋅ mol
T = 25˚C + 273 = 298 K; V = 20.0 L
Substituting,
P =
(2.38 mol H2 )(0.0821 L ⋅ atm/K ⋅ mol)(298 K)
= 2.91 atm
20.0 L
The Greenhouse Effect and Global Warming
According to the National Academy of Sciences, the Earth's surface temperature has risen by about 1
degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is
new and stronger evidence that most of the Global warming over the last 50 years is attributable to
human activities. Human activities have altered the chemical composition of the atmosphere through the
buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide
Dalton's Law of Partial Pressures
John Dalton studied the effect of gases in a mixture. He observed that the Total Pressure of a gas
mixture was the sum of the Partial Pressure of each gas.
P total = P1 + P2 + P3 + .......Pn
The Partial Pressure is defined as the pressure of a single gas in the mixture as if that gas alone occupied
the container. In other words, Dalton maintained that since there was an enormous amount of space
between the gas molecules within the mixture that the gas molecules did not have any influence on the
motion of other gas molecules, therefore the pressure of a gas sample would be the same whether it was
the only gas in the container or if it were among other gases.
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Problem: A gaseous mixture containing helium (He) and neon (Ne), has 0.56 atm of total pressure. If
the partial pressure of He is 0.27 atm, what would be the partial pressure of Ne?
Answer:
P = P
t
P
P
P
Ne
Ne
Ne
He
+P
=P –P
t
Ne
He
= 0.56 atm – 0.27 atm
= 0.29 atm
Kinetic Molecular Theory of Gases
The kinetic energy is energy possessed by a body by virtue of its motion. The kinetic energy of a body is
equal to the amount of work needed to establish its velocity and rotation, starting from rest.
According to Kinetic-Molecular Theory any gas is composed of a very large number of very
tiny particles called molecules.
This theory explains the behavior of gases on the basis of the following assumptions:
Postulated of kinetic-molecular theory of gases
1. Any gas is composed of a very large number of molecules move in straight lines; their direction is
random.
2. Molecules are small. (The volume they occupy is small compared to the total V.)
3. Molecules do not attract or repel each other (no intermolecular forces).
4. Elastic collisions i.e., they take place within a negligible span of time and does not lose kinetic
energy.
5. Average kinetic energy is proportional to T(K).
A gas corresponding to these assumptions is called an ideal gas; as the temperature of a real gas
is lowered, or its pressure is raised, its behavior no longer resembles that of an ideal gas because one or
more of the assumptions of the theory is no longer valid.
Ideal Gases Versus Real Gases
An ideal gas is a theoretical idea – a gas in which there are no attractive forces between the
molecules, and in which the molecules take up no space. Both of these assumptions are incorrect.
If there were no attractive forces between molecules, no substances would ever condense from the
gas state to become liquids and solids. In fact, every substance does condense when it is cooled
and compressed enough. Therefore there must be attractive forces between molecules.
•
If molecules took up no space, then we could compress substances until they had no volume at
all. In fact, solids and liquids are almost incompressible, since their molecules are basically
touching each other. Since solids and liquids take up space, the molecules of which they are
made must take up space also.
However:
•
When the pressure is fairly low (around atmospheric pressure or less) the molecules are not very
close to each other. The intermolecular attractions and molecular size are not very important
under these conditions.
•
When the temperature is fairly high (perhaps 100 oC or more above the substance's boiling
boint) the attractive forces are not very important compared to the rapid motion of the molecules
Under these conditions, a gas will behave nearly ideally. This is true for things we readily identify as
gases at room temperature and pressure conditions, like hydrogen, nitrogen and oxygen. These real
gases are said to behave ideally – that is, they obey the ideal gas law.
z
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The Liquid State
When considering the three states of matter, the middle state is known as the Liquid State. It has
some of the characteristics of the solid state and some of the characteristics of the gas state.
z Like the gas state, the liquid state tends to flow, or have fluidity.
z Like the gas state, the liquid state tends to take on the shape of the container that it is in.
z Like the solid state, the liquid state is associated with somewhat low kinetic energy.
Compressibility
Unlike the gaseous state liquid state has cannot be compressed. Like the solid state, the liquid state tends
to have very little ability to be compressed. The fact break fluid in a vehicle works with no air leaks into
break line is based on non compressibility of liquids.
Viscosity
Viscosity is a measure of a fluid's resistance to flow. Liquids such as molasses or motor oil are examples
of highly viscous substances. The viscosity of a liquid generally decreases as the temperature is
increased. Gases also have a resistance to flow, although these viscosities are much lower than for
liquids.
Blood Gases and Respiration
Blood gas measurements are used mainly to evaluate the severity of an O2/CO2 or pH imbalance.
Surface Tension
A molecule I in the interior of a liquid is under attractive forces in all directions and the vector
sum of these forces is zero. But a molecule S at the surface of a liquid is acted by a net inward cohesive
force that is perpendicular to the surface. Surface tension is the tendency of the surface of a liquid to
behave like a stretched elastic membrane. There is a natural tendency for liquids to minimize their
surface area. For this reason, drops of liquid tend to take a spherical shape in order to minimize surface
area. For such a small droplet, surface tension will cause an increase of internal pressure p in order to
balance the surface force.
A molecule I in the interior of a liquid is under attractive forces in
Vapor Pressure of a Liquid
One of the most fundamental qualities of a liquid is the vapor pressure that the liquid produces.
Vapor is the term that is used to describe the gas phase material that is located directly above the liquid
phase. By knowing the vapor pressure of a liquid, many qualities of that liquid are implied.
Vapor pressure is the pressure that is exerted by gas phase units that are leaving the surface of a liquid.
The molecules leaving the liquid phase depend on the types of intermolecular forces present in the
liquid.
1) London Dispersion (Van der Waals) Forces (Lowest vapor pressure)
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2) Dipole-dipole Forces
3) Hydrogen Bonding (Highest vapor pressure)
The Solid State
The solid state is the most highly ordered state of matter; the strong attractive forces between
particles impart a definite shape to the solid. Solids are incompressible. Solids may be crystalline
(regular, repeating structure) or amorphous (without organized structure). The crystalline solids may be
classified into four major groups: ionic solids, covalent solids, molecular solids, or metallic solids. The
solid state of matter is when the material has a definite volume or size and distinct shape at a given
temperature. A piece of iron at room temperature has a shape and size that does not change. Ice is
another solid, but its temperature must be below 0o C (32o F).
Properties of Solids
Physical properties: Density, m.p., b.p,
Mechanical properties: Strong and weak
Thermal properties: Good thermal conductors and poor thermal conductors (thermal insulators)
Electrical properties: Conductors, Semiconductors, and Insulators.
Types of Solids
Solids can be divided in to two distinct classes.
1) Crystalline solids
2) Amorphous solids
3) Polymeric
Crystalline
Example Diamond
Crystalline solids are based
upon a simple pattern of
arrangement of molecules that
is repeated many times
throughout the molecule often
Structure
there will be boundaries in the
material where the pattern
cannot be continued, these give
rise to the edges of crystals and
a polycrystalline material.
Amorphous
Glass
Polymeric
Polyethylene
Amorphous solids have no
regular arrangement. They
are made up of
long arrangement of their
molecules and appear like
an instantaneous photo of
a liquid, some like glass
show flow very slowly.
Polymeric solids are
made up of long
chain molecules,
wrapped around each
other. The polymer
chains are made up of
repeating monomers.
Crystalline solids
Crystalline solids have the following fundamentals properties.
1. They have characteristic geometrical shape.
2. They have highly ordered three-dimensional arrangements of particles.
3. They are bounded by PLANES or FACES
4. Planes of a crystal intersect at particular angles.
5. They have sharp melting and boiling points.
Examples:
Copper Sulfate (CuSO4), NiSO4, Diamond, Graphite, NaCl, Sugar etc
Amorphous Solids
Solids that don’t have a definite geometrical shape are known as Amorphous Solids.
1. In these solids particles are randomly arranged in three dimensions.
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2. They don’t have sharp melting points.
3. Amorphous solids are formed due to sudden cooling of liquid.
4. Amorphous solids melt over a wide range of temperature
5. Examples: Coal, Coke, Glass
Polymeric solids
The structure of polymeric material is rather complex. The juxtaposition of the various structural
elements that make up the morphology of a polymer depends on chemical composition, thermal and
mechanical history, and the length scale being considered. What looks homogeneous at one
magnification may appear quite heterogeneous at another. There are few areas of ordered structure
called crystalline domains in some polymers These domains are characterized by an ordered
arrangement of the polymer chains from which they are composed. Rest of the polymer considered
amorphous. These amorphous domains contain disordered polymer chains.
Types of Crystalline Solids
a) Molecular Solids
b) Ionic Solids
c) Network Solids
d) Metallic Solids
a) Molecular or Covalent Solids: In molecular crystals repeating unit of the crystal is a molecule. The
forces holding molecular crystals could be either dipole-dipole as in water or London dispersion as in
purple crystals of I2.
E.g. H2, I2, H2O, CO2, CH4, Molecules held together by covalent CH3OH, CH3CO2H bonds
b) Ionic Solids: In ionic crystals the repeating units are cations, Nat and anions, Cl- as in a NaCI(s)
crystal. These ions are held strongly by the ionic bonds or the electrostatic attractions between Na+ and
Cl- ions. The force holding the ionic crystal lattice is called the ionic bond.
E.g. NaCl, K2SO4, CaCI2. Positive and negative ions; no discrete (NH4)3PO4 molecules
c) Network Solids or Network Covalent Solids:
The repeating units are held together by covalent bonds to form a giant orderly molecules such as
a diamond or graphite, or silicon crystal.
E.g. Graphite, diamond, quartz, Atoms held in an infinite one-, two-, feldspars, mica or threedimensional network
d) Metallic Solids: Metallic solid consists of metal atoms regularly arranged to a three-dimensional
lattice. Forces holding them are called metallic, i.e. bonds which are different from either the dipoledipole attractions in molecular solids, the ionic bonds in ionic solids, or the covalent bonds in network
solids. Usually metals, the elements with fewer electrons from metallic solids because metals cannot
complete their octet by forming covalent bonds with another metal atom. Metals share electrons with all
metal atoms in the solid. This sharing leads to a cloud of free electrons which is delocalized all over the
entire material. Bonding shown in these types of metallic solids is called metallic bond. E.g. Iron, silver,
copper, other metal atoms (or positive metal ions metals and alloys surrounded by an electron sea).
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Homework 6. Chapter 6
1. Which of the following does not accurately describe a characteristic of gases?a. Gas molecules can
be "squeezed together" to fit into a container.
b. The gas we exhale expands out continuously into the atmosphere.
c. The vapors of two immiscible liquids (liquids that do not mix together, but form separate layers) will
mix completely.
d. If a large container is filled with a small amount of gas, the gas will occupy only a portion of the
container.
e. One must include the temperature, pressure, volume occupied and number of moles or molecules to
completely describe a gas.
2. Convert 699 torr to 1) atm, 2) mmHg and 3) kPa.
1) atm
2) mmHg
3) kPa
5
Option 1: 5.31 × 105
93.2
5.31 × 10
Option 2: 0.920
699
93.2
Option 3: 699
5.24 × 103
5.31 × 105
Option 4: 6.90
6.995 × 105
7.08 × 104
Option 5: 0.920
699
9.32 × 104
a. Option 1 b. Option 2 c. Option 3 d. Option 4 e. Option 5
3. A given mass of oxygen at room temperature occupies a volume of 500.0 mL at 1.50 atm
pressure. What pressure must be applied to compress the gas to a volume of only 150.0 mL?
a. 500 atm b. 150 atm c. 5.00 atm d. 1.50 atm e. 0.500 atm
4. How many moles of gas are there in a gas-filled balloon which has a volume of 67.0 L at a
pressure of 742 mmHg and a temperature of 25.0°C?
a. 2.24 mol
b. 2.67 mol
c. 2.81 mol
d. 31.9 mol
e. 1.71 x 103 mol
5. Carbon dioxide acts as a greenhouse gas by
a. absorbing visible radiation
b. absorbing ultraviolet radiation c. absorbing infrared radiation
d. storing solar energy
e. trapping sunlight during photosynthesis
6. Which of the following does the Kinetic-Molecular Theory assume?
a.
A gas is composed of atoms or molecules whose size is proportional to the distance
between them. (Large distance, large atom or molecule)
b.
The average kinetic energy of a gas molecule increases as the temperature increases.
c.
Gas molecules are moving randomly in various directions at one speed.
d.
The forces of attraction and repulsion between gas molecules are proportional to the size
of the molecule.
e.
Small amounts of energy are lost with each collision of gas molecules.
7. Of the following gases, which will behave most like an ideal gas?
a. N2
b. HF c. NH3 d. H2O e. CO
8. Consider a gas mixture of 21% O2, 78% N2, 0.5% CO2 and trace amounts of Ar. Which of the
following represents the total pressure exerted by the mixture?
a. P(O2) + P(N2) + P(CO2) b. P(O2) + P(N2) + P(CO2) + P(Ar)
d. P(N2)
c. P(O2) + P(N2)
e. The pressure of the mixture is independent of the partial pressures of the individual gases.
9. The best explanation for the existence of a meniscus observed when water is placed in a glass
tube of small diameter is
a. the viscosity of the water is greater than the viscosity of the glass.
b. surface tension of the water causes it to "bead up" inside the container.
c. the molecules are forced closer together because of London forces.
d. the adhesive forces between the water molecules and the walls are greater
than the cohesive forces between the water molecules.
e. the hydrogen bonds between water molecules are greater than the attractions between the
water molecules and the walls of the container.
10. What is the term that describes a solid changing to a vapor at a temperature less than its meting
point?
a. evaporation
b. Sublimation c. Dissociation d. Condensation e. supercooling
11. Which of the following statements concerning liquids is(are)true?
1. Liquids diffuse slowly when compared with solids.
2. Volatile liquids have higher vapor pressures at room temperature.
3. The volume of a liquid does not changes with pressure.
a. 1 only b. 2 only c. 3 only
d. 1 and 2 only
e. 2 and 3 only
12. Which of the following molecule wouldn’t show hydrogen bonding?
13. CaCl2, calcium chloride, is a
a. polar molecular solid
b. nonpolar molecular solid
c. covalent network solid
d. ionic solid
14. Which of following solids does not have covalent network structure ?
a. NaCl b. C(graphite) c. C(diamond) d.SiO2 (quartz)
15. Which choice is an example of an polymeric amorphous solid?
a. nylon
b. potassium sulfate
c. potassium
d. iodine
e. quartz
Chapter 6, States of Matter: Gases, Liquids, and Solids
1.
Which two states of matter are the least compressible?
Ans.
2.
solids and liquids
What device is used to measure atmospheric pressure?
Ans.
3.
barometer
The pascal (Pa) is a unit for expressing what quantity?
Ans.
4.
pressure
What experimental quantity measures force per unit area?
Ans.
5.
pressure
State Boyle's Law.
Ans.
The volume of a gas is inversely proportional to the pressure, if the
number of moles (or mass) and the temperature of the gas are kept
constant.
State Charles's Law.
6.
Ans.
7.
Ans.
8.
The volume of a gas is directly proportional to the absolute
temperature, if the number of moles (or mass) and the pressure of the
gas are kept constant.
State Avogadro's Law.
Equal volumes of any ideal gas, at the same temperature and pressure,
contain the same number of moles.
What law predicts the expansion of a balloon when helium is added?
Ans.
9.
Avogadro's
Consider 1.00 L of air in a patient's lungs at 37.0°C and 1.00 atm
pressure. What volume would this air occupy if it were at 25.0°C under
a pressure of 5.00 × 102 atm (a typical pressure in a compressed air
cylinder)?
Ans.
10.
19.2 × 10-3 L
If a gas sample is at STP (Standard Temperature and Pressure), what are
its temperature and pressure?
Ans.
11.
temperature = 0.0°C or 273 K, pressure = 1.00 atm.
Calculate the density of oxygen gas (O2) at STP, in g/L. [Use molar
mass: O2, 32.0 g/mol]
Ans.
12.
1.43 g/L
What is the volume (L) occupied by a mole of an ideal gas, if the
pressure is 626 mmHg and the temperature is 25.0°C?
Ans.
13.
29.7 L
Who found that a mixture of gases exerts a total pressure that is the
sum of the pressures that each gas would exert if each were present
alone under similar conditions?
Ans.
Dalton
General, Organic, and Biochemistry, 3/e
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Chapter 6, States of Matter: Gases, Liquids, and Solids
14.
An gas sample is prepared in which the components have the following
partial pressures: nitrogen, 555 mmHg; oxygen, 149 mmHg; water vapor,
13 mmHg; argon, 7 mmHg. What is the total pressure of this mixture?
Ans.
15.
724 mmHg
What is the name of the theory which deals with particle behavior in
the gas phase?
Ans.
16.
kinetic molecular theory
Choose the best one from each pair in the following sentence: The
closest approach to ideal gas behavior will be shown by (NH3 or H2?) at
(low or high?) pressure and (low or high?) temperature.
Ans.
17.
H2, low, high
What is meant by viscosity?
Ans.
18.
It is the resistance of a liquid to flow.
What experimental quantity is a measure of the attractive forces
between molecules at the surface of a liquid?
Ans.
19.
surface tension
What process is responsible for the formation of dew on the grass early
in the morning?
Ans.
20.
condensation
How can pure water be made to boil at a temperature above 100°C?
Ans.
21.
by raising the pressure to more than one atmosphere
Who postulated the existence of temporary dipole attraction among
nonpolar molecules?
Ans.
22.
Fritz London
What are the general structural requirements for a compound to display
hydrogen bonding?
Ans.
It must have hydrogen atoms bonded to small, electronegative atoms such
as N, O or F.
Why is hydrogen bonding more extensive in water than in hydrogen
fluoride?
23.
Ans.
24.
Ans.
Each water molecule has two δ+ sites and two δ- sites, all of which can
be used for hydrogen bonding. The hydrogen fluoride has three δ- sites
but only one δ+ site, and the shortage of the latter limits the number
of hydrogen bonds which can form per molecule to half the number in
water.
Name the four main types of crystalline solid, and give an example of
each.
ionic solid, NaCl; covalent solid, diamond; molecular solid, ice;
metallic solid, iron.
General, Organic, and Biochemistry, 3/e
Page 39
Chapter 6, States of Matter: Gases, Liquids, and Solids
25.
A barometer measures
A.
B.
C.
D.
E.
Ans.
26.
D
Who invented the first barometer?
A.
B.
C.
D.
E.
Ans.
27.
14.7 mm Hg
380 mm Hg
760 mm Hg
0.333 mm Hg
30 mm Hg
C
Which one of the following pressures is NOT equal to one atmosphere?
A.
B.
C.
D.
E.
Ans.
Boyle
Charles
Dalton
Gay-Lussac
Torricelli
E
Express one standard atmosphere of pressure in units of mm Hg.
A.
B.
C.
D.
E.
Ans.
28.
the pressure of a gas sample in a container
the difference in pressure between two gas samples
the difference in pressure between a gas sample and atmospheric
pressure
atmospheric pressure
the pressure of an ideal gas
76 cm Hg
14.7 lb/in2
30 inches of Hg
101 kPa
76 torr
E
General, Organic, and Biochemistry, 3/e
Page 40
Chapter 6, States of Matter: Gases, Liquids, and Solids
29.
A
B
E
C
D
0
0
Pressure (atm )
In the graph shown above, which line is the best representation of
Boyle's Law behavior of a gas?
A.
Ans.
30.
C
D.
E.
D
E
Boyle
Charles
Dalton
Gay-Lussac
Torricelli
3.00 L
1.50 L
0.667 L
0.500 L
0.333 L
E
A given mass of oxygen at room temperature occupies a volume of 500.0
mL at 1.50 atm pressure. What pressure must be applied to compress the
gas to a volume of only 150.0 mL?
A.
B.
C.
D.
E.
Ans.
C.
A
A sample of oxygen occupies 1.00 L. If the temperature remains
constant, and the pressure on the oxygen is tripled, what is the new
volume?
A.
B.
C.
D.
E.
Ans.
32.
B
E
Who formulated the relationship between the volume and the pressure of
a gas?
A.
B.
C.
D.
E.
Ans.
31.
B.
A
500 atm
150 atm
5.00 atm
1.50 atm
0.500 atm
C
General, Organic, and Biochemistry, 3/e
Page 41
Chapter 6, States of Matter: Gases, Liquids, and Solids
33.
Who formulated the relationship between the volume and temperature of a
gas?
A.
B.
C.
D.
E.
Ans.
34.
B
A balloon filled with helium has a volume of 1.00 × 103 L at 20°C. What
would be the balloon's volume at 30°C, if the pressure surrounding the
balloon remains constant?
A.
B.
C.
D.
E.
Ans.
35.
Boyle
Charles
Dalton
Gay-Lussac
Torricelli
6.7 × 102 L
9.70 × 102 L
1.03 × 103 L
1.11 × 103 L
1.50 × 103 L
C
0
0
Temperature (K)
Who discovered the gas law represented in the figure above?
A.
B.
C.
D.
E.
Ans.
36.
B
What is the volume occupied by one mole of helium at 0°C and 1 atm
pressure?
A.
Ans.
Boyle
Charles
Dalton
Gay-Lussac
Torricelli
1.0 L
B.
22.4 L
C.
4.0 L
D.
40.0 L
B
General, Organic, and Biochemistry, 3/e
Page 42
E.
12.2 L
Chapter 6, States of Matter: Gases, Liquids, and Solids
37.
A helium-filled weather balloon is launched from the ground where the
pressure is 752 mmHg and the temperature is 21°C. Under these conditions
its volume is 75.0 L. When it has climbed to an altitude where the
pressure is 89 mmHg and the temperature is 0°C, what is its volume?
A.
Ans.
38.
C.
D.
E.
9.56 L
D.
588 L
E.
682 L
2.24
2.67
2.81
31.9
1.71
mol
mol
mol
mol
× 103 mol
absorbing visible radiation
absorbing ultraviolet radiation
absorbing infrared radiation
storing solar energy
trapping sunlight during photosynthesis
There are no forces between gas particles.
Gas particles occupy a negligible volume compared with the volume of
their container.
The average kinetic energy of the gas particles is proportional to
the absolute temperature.
Gas particles lose energy only when they collide with the walls of
the container.
Gas particles are in constant, random motion.
D
What quantity is directly proportional to the kinetic energy of the
particles in a gas?
A.
B.
C.
D.
E.
Ans.
C.
C
Which of the following statements conflicts with the kinetic molecular
theory of gases?
A.
B.
Ans.
41.
8.24 L
B
Carbon dioxide acts as a greenhouse gas by
A.
B.
C.
D.
E.
Ans.
40.
B.
D
How many moles of gas are there in a gas-filled balloon which has a
volume of 67.0 L at a pressure of 742 mmHg and a temperature of 25.0°C?
A.
B.
C.
D.
E.
Ans.
39.
0.00 L
distance between molecules
absolute temperature
atomic mass
formula mass
volume of the individual particles.
B
General, Organic, and Biochemistry, 3/e
Page 43
Chapter 6, States of Matter: Gases, Liquids, and Solids
42.
Of the following gases, which will behave most like an ideal gas?
A.
Ans.
43.
NH3
D.
CH3Cl
E.
CO
vapor pressure
surface tension
resistivity
viscosity
compressibility
equal
proportional
zero
lower
higher
increases with increasing temperature
is unaffected by temperature
is higher for nonpolar substances than for polar ones
is lowered by surfactants
is the same as viscosity
D
What is the term that describes a liquid changing to a vapor at a
temperature less than its boiling point?
A.
B.
C.
D.
E.
Ans.
C.
E
Surface tension
A.
B.
C.
D.
E.
Ans.
46.
HF
D
At the membrane barrier in lung tissue between the blood and the
surrounding atmosphere, what is the relationship between the partial
pressure of atmospheric oxygen to that of the oxygen present in the
blood?
A.
B.
C.
D.
E.
Ans.
45.
B.
A
What is the experimental quantity that serves as a measure of
resistance to flow of a liquid?
A.
B.
C.
D.
E.
Ans.
44.
H2
evaporation
sublimation
dissociation
condensation
supercooling
A
General, Organic, and Biochemistry, 3/e
Page 44
Chapter 6, States of Matter: Gases, Liquids, and Solids
47.
Which one of the following substances with their structures shown, will
NOT display hydrogen bonding?
H
H
O
N
H
H
H
O
F
H
H
H
H
H
C
H
H
C
H
C
O
H
C
H
A. NH3
A.
Ans.
48.
E
T
B.
A
F
B. HF
B
C. H2O
C.
D. ethanol
C
H
H
H
E. diethyl ether
D.
E.
D
E
Gases and liquids are both highly compressible.
49.
Ans.
T F
F
The density of a gas is proportional to its molecular weight.
50.
Ans.
T F
T
Dalton's Law states that the volume of a gas varies directly with
the absolute temperature.
51.
Ans.
T F
F
Approximately 99% of the total pressure of dry air is due to
molecules of N2 and O2.
52.
Ans.
T F
T
The average energy of an ideal gas molecule depends on the
molecular weight of the gas.
53.
Ans.
T F
F
Polar gases are more ideal than nonpolar ones.
54.
Ans.
T F
F
As temperature increases, so does viscosity.
55.
Ans.
T F
F
Glycerol has a lower viscosity than ethanol.
56.
Ans.
T F
F
The surface tension of water is reduced by the addition of soap.
57.
Ans.
T F
T
The boiling point of a liquid is dependent on the atmospheric
pressure.
58.
Ans.
T F
T
The boiling point of a liquid increases with increasing altitude.
Ans.
F
General, Organic, and Biochemistry, 3/e
Page 45
Chapter 6, States of Matter: Gases, Liquids, and Solids
59.
T
F
60.
Ans.
T F
T
All compounds containing both oxygen and hydrogen will exhibit
hydrogen bonding.
61.
Ans.
T F
F
Ionic compounds tend to have higher melting points than molecular
compounds.
62.
Ans.
T F
T
Covalent solids are soft and readily soluble in many solvents.
63.
Ans.
T F
F
Metals conduct electricity well due to the mobility of the metal
ions in the solid.
Ans.
F
Polar compounds generally have higher boiling points than
nonpolar compounds of similar molecular weight.
General, Organic, and Biochemistry, 3/e
Page 46
Chapter 7, Reactions and Solutions
1.
Classify the following reaction as precipitation, acid-base or
oxidation-reduction:
Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)
Ans.
2.
oxidation-reduction
Classify the following reaction as precipitation, acid-base or
oxidation-reduction:
H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(aq)
Ans.
3.
acid-base
Classify the following reaction as precipitation, acid-base or
oxidation-reduction:
Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s)
Ans.
4.
precipitation
Complete the products and balance the following equation for an acidbase reaction:
HCl(aq) + KOH(aq)
Ans.
5.
HCl(aq) + KOH(aq) → KCl(aq) + H2O(l)
Complete the products and balance the following equation for a
precipitation reaction:
FeSO4(aq) + NaOH(aq)
Ans.
6.
FeSO4(aq) + 2NaOH(aq) → Fe(OH)2(s) + Na2SO4(aq)
Write a balanced equation for the reaction between zinc metal and
iron(III) ions to form zinc(II) ions and iron(II) ions (Symbols: zinc =
Zn; iron = Fe).
Ans.
7.
Zn(s) + 2Fe3+(aq) → Zn2+(aq) + 2Fe2+(aq)
Name the two products formed when octane (C8H18) burns completely in
excess oxygen gas.
Ans.
8.
carbon dioxide and water
Classify the following reaction as decomposition, combination, singlereplacement or double-replacement:
2H2O(l) → 2H2(g) + O2(g)
Ans.
9.
decomposition
Classify the following reaction as decomposition, combination, singlereplacement or double-replacement:
H2SO4(aq) Ba(OH)2(aq) → BaSO4(s) + 2H2O(g)
Ans.
10.
double-replacement
Classify the following reaction as decomposition, combination, singlereplacement or double-replacement:
Mg(s) + 2HCl(aq) → MgCl2(g) + H2(g)
Ans.
single-replacement
General, Organic, and Biochemistry, 3/e
Page 47