CP Chemistry
Chapter 10:
States of Matter
Name: _____________________________
Mods: ______________
Chapter 10: States of Matter
Reading Guide
10.1 – The Kinetic Molecular Theory of Matter (pgs. 311-314)
1.
The kinetic-molecular theory (KMT) is based upon the idea that ________________ of
matter are ________ in _____________.
2. The kinetic-molecular theory explains the constant motion of gas particles. The theory
provides a model of what is called an ideal gas.
Define ideal gas:
Define elastic collision:
3. Summarize the five (5) assumptions that kinetic-molecular theory is based on: (2 -3 sentences
each)
(1)
(2)
(3)
(4)
(5)
4. What happens to the average speed of gas particles as their temperature is increased?
5. Answer the below questions from what you have read so far about KMT:
(a) What would happen if you transferred a quantity of a gas from a 1-liter bottle to a 2-liter bottle?
(b) Why are liquids and gases both considered fluids?
(c) Why do gases have such low densities as compared to liquids and solids?
6.
Explain the difference between effusion and diffusion
7.
Define a real gas:
8.
Critical thinking: Look at graphic 1.3 on page 314. What will eventually happen to the gas if it
is compressed enough?
10.2 – Liquids (pgs. 315-318)
9.
What determines the properties of liquids?
10.
Define surface tension and provide an example:
11.
Define capillary action and provide an example:
10.3 – Solids (pgs. 319-323)
12.
Complete the matching section below.
a.
b.
covalent network crystals
metallic crystals
c. covalent molecular crystals
d. ionic crystals
________ 1.
consists of covalently bonded molecules held together by intermolecular forces.
________ 2.
consists of positive and negative ions arranged in a regular pattern.
________ 3.
metal cations surrounded by a sea of delocalized valence electrons.
________ 4.
each atom is covalent bonded to its nearest neighboring atoms.
10.4 – Changes of State (pgs. 319-323)
13.
During phase changes, the states of matter are in equilibrium with one another; they change
back and forth between the states of matter at equal speeds
14.
Define the following terms:
Phase:
15.
A gas in contact with its liquid or solid phase is called a ___________________.
16.
Review figure 4.2. Describe the rates of evaporation and condensation when they are at
equilibrium:
States of Matter: the Molecular Perspective
1. States of Matter – “definite” or “indefinite” volume and shape
State of Matter
Volume
Shape
2. States of Matter – Visual representation of how the atoms/molecules are organized
Solid:
Liquid:
very ordered arrangement
particles in fixed positions
does not flow
particles vibrate in place
very close to one another
ridged crystalline structure
retains its shape & volume
virtually incompressible
condensed phase
Gas:
less ordered arrangement
particles are free to move
readily flows
particles move quickly
particles are close together
assumes shape of container
constant volume
virtually incompressible
condensed phase
total disorder of particles
readily flows
particles move extremely fast
particles very far apart
complete freedom of motion
assumes shape of container
variable volume
much empty space
easily compressed
3. At a given temperature and pressure, the state of matter of a substance depends on 2 quantities:
(1) _________________ ______________ of particles:

KE is the energy of ____________________. At higher temperatures, particles will
move ___________________. As a result, KE and temperature are
____________________ proportional
(2) Strength of _________________________ between particles:

Forces of attraction bond particles together. Generally, the closer together the particles
are to each other, the ______________________ the attraction between them
 How does KE and strength of attraction explain properties of solids, liquids, and gases?

Solids – have very ____________ KE (particles vibrate in place) and have very
________________ forces if attraction; this keeps the partciles tightly bound together in
a ridged, orderly structure

Gases – have very ____________ KE (particles are fast moving) and have very
________________ forces of attraction because the particles are so far apart from one
another
4. Phase Changes – there are two ways to change the state of matter of a substance:
(1) Changes in temperature:

When matter is heated, temperature & KE increases, causing particles to move faster
and spread appart, thus ___________________ the forces of attraction (at a certain
point, the KE is great enough to overcome the forces of attraction between the particles)

When matter is cooled down, the oppsite occurs and the forces of attraction become
___________________ (now the KE is not great enough to overcome the attraction)
(2) Changes in pressure:

Applying pressure to matter will force the particles ____________________ to one
another, reducing their motion and thus ___________________ the strength of attraction
between the particles

Typically the _____________ state of matter is most affected by to changes in pressure
Change of State
solid  liquid
liquid  gas
solid  gas
gas  solid
gas  liquid
liquid  solid
Process
Example
Phase Diagrams – In Class Notes
1)
A phase diagram is a graph of pressure vs. temperature that shows the conditions at which the
phases of the substance exist. It also shows how the phases change with changing temperatures
and pressures.
2)
Key Parts of a Phase Diagram:
a) States of Matter:

Solids exist at _____________ pressures and ____________ temperatures, while gases
exist _____________ pressures and ____________ temperatures
b) Atmospheric Pressure:

This is the pressure our atmosphere exerts on us (at sea level). There are several units for
pressure, but all of the following are equal each another and reflect atmospheric pressure:
____atm (atmosphere) = ______torr = _______mm Hg (millimeters of mercury) = ___________kPa (kilopascal)
c) Melting & Boiling Points:

Melting Point – the temperature at which a substances changes from a solid to liquid; this
phase change occurs when the solid and liquid states are in equilibrium with one another

Boiling Point – the temperature at which a substances changes from a liquid to gas; this
phase change occurs when the liquid and gas states are in equilibrium with one another
o
All substances have only one NORMAL melting point and one NORMAL boiling
point which occur at __________________________ pressure
o
If the pressure is changed to something other than atmospheric pressure, then the
substance will have different melting and boiling points
d) Triple Point – indicates the temperature & pressure conditions at which the solid, liquid, and
gas phases of a substance _______________ at the same time in equilibrium with each other
e) Critical Point - the temperature & pressure at which there is no longer distinct
________________ and ________________ phases

Once a substance reaches the critical point or exceeds the critical temperature or critical
pressure, it becomes a supercritical fluid

Supercritical Fluid – the substance exhibits behaviors of both liquids and gases (it can
behave as a gas, both effusing & diffusing, but it can also dissolve other substances like a
liquid).
Phase Diagram of Bromine (Br2) – In Class Example
[Note that the scales are distorted to emphasize some of the graph’s features]
Directions: Answer the questions below using the phase diagram of bromine.
1) Label the states of matter in the appropriate places on the phase diagram above.
2) Identify the phase changes that occur on the line next to points A, B, and C on the diagram.
A: __________________________________and __________________________________
B: __________________________________and __________________________________
C: __________________________________and __________________________________
3) Label bromine’s normal melting point (MP), normal boiling point (BP), triple point (TP), &
critical point (CP) on the diagram & estimate the temperature & pressure values at each point:
Temperature (ᵒC)
Pressure (kPa)
Temperature (ᵒC)
Normal MP
Triple Point
Normal BP
Critical Point
Pressure (kPa)
4) Looking at the diagram, describe what happens to the melting point of bromine as the external
pressure increases.
What can you conclude about the forces of attraction between the bromine molecules as the
pressure increases?
What is the relationship between the melting point (or boiling point) of a substance and the
strength of attractive forces between its molecules?
5) If you keep the temperature of a substance constant, but increase the pressure the more
dense state of matter is always favored. If you look at the slope of the melting-point equilibrium
line, a positive slope (as seen with bromine) means that with increasing pressure will favor the
_________________ state as the more dense state of matter. Rarely, a substance may have
a negative slope signifying that the ________________ state of matter would be denser. An
example of a substance like this would be _____________________
6) What is the boiling point of bromine when the external pressure is 75 kPa? _______________
7) Complete the following sentences by filling in to correct phase change that occurs:
a) Bromine gas at 15°C will ______________________________ when the pressure is raised
from 10 kPa to 50 kPa.
b) Br2 liquid at 70 kPa _______________________________ when the temperature is
decreased from 20°C to –15°C.
c) Bromine solid at –20°C will undergo _____________________________ is the pressure is
increased from 0 kPa to 10 kPa.
Phase Diagram of Water – In Class Example
1) Describe all the phase changes a sample of solid water would undergo when heated from 10°C to its critical temperature at a constant pressure of 1.00 atm.
2) Describe all the phase changes a sample of water vapor would undergo when cooled from
110°C to 5°C at 1.00 atm of pressure.
3) At what pressures will water be a vapor at 0°C? ___________________________________
4) Within what range of pressures will water be a liquid at temperatures above its normal boiling
point?
Phase Diagrams – Homework WS #1
Directions: Refer to the phase diagram below when answering the questions on this worksheet:
1) At atmospheric pressure at room temperature (27ᵒC), what state of matter is this substance?
2) What is the normal melting point of this substance? _________________
3) What is the normal boiling point of this substance? _________________
4) What is the normal freezing point of this substance? _________________
5) If I had a quantity of this substance at a pressure of 1.25 atm and a temperature of 300ᵒC and
lowered the pressure to 0.25 atm, what phase transition(s) would occur?
6) At what temperature and pressure do the gas and liquid phases become indistinguishable
from each other? What is this point called?
7) If I had a quantity of this substance at a pressure of 0.50 atm and a temperature of –100ᵒC,
what phase change(s) would occur if I increased the temperature to 600ᵒC? At what
temperature would this occur?
8) Under what conditions of temperature and pressure are all three states of matter in
equilibrium? What is this point called?
Phase Diagrams – Homework WS #2
Use the phase diagram for water below to answer the following questions.
1) Label the three states of mater on the diagram above.
2) What is standard atmospheric pressure on this graph? _______________________ [look at
units]
3) What is the normal melting point of this substance? _____________________
4) What is the normal boiling point of this substance? _____________________
5) At atmospheric pressure and room temperature (27°C), what state of mater is this substance?
6) If the external pressure was raised to 160 kPa, what would be the new melting and boiling
points of this substance?
7) What phase change occurs when a substance at 60 kPa and 0°C has its pressure lowered to
10 kPa?
8) At what temperature and pressure is the critical point? What is the critical point?
Phase Diagrams – Homework WS #3
Use the phase diagram for water below to answer the following questions.
Carbon dioxide is a unique substance, hence its very a-typical phase diagram. The
states of matter have been labeled to help assist you in answering the questions below.
1) At atmospheric pressure and room temperature (27ᵒC), what state of matter is the substance?
2) At the point labeled -78.5ᵒC at 1 atm, what phase change is occurring? What would we call
this point?
3) What is happening at the conditions of -56.6ᵒC at 5.11 atm?
4) It is very difficult to get CO2 into the liquid phase. At a temperature of –40.0ᵒC it is possible to
melt solid CO2 into a liquid; what pressure would be necessary to do this?
5) Under what range of pressure conditions would CO2 be a liquid at –20.0ᵒC?
Vapor Pressure Curves – In Class Example
VAPOR PRESSURE GRAPHS: Use the graph shown below to answer the following questions.
1) Define vapor pressure.
2) Looking at the curves, what is the general trend for vapor pressure as temperature increases?
Why does this make sense?
3) What is a volatile liquid?
4) Which substance in the graph is
the most volatile?
5) What is the vapor pressure of
CHCl3 at 50C?
6) What is the boiling point of H2O
when the external pressure is 30
kPa?
7) What is the normal boiling
point of CCl4?
8) Which substance has the
weakest intermolecular forces of
attraction (IMFs)?
9) Explain the relationship between IMFs and vapor pressure?
Pressure, Boiling Points, and Real Life Applications
1) At sea level, atmospheric pressure is approximately 1 atm. Denver, Colorado is known as
the “mile high city” since it is exactly 5280 feet above sea level.
a) Do you expect the atmospheric pressure in Denver to be higher or lower than 1 atm?
b) Based on your answer to part a, would you expect a pot of water in Denver to have a
higher or lower boiling point than 100ᵒC? Why?
c)
What does this mean in terms of time it takes to cook pasta in Denver?
2) Many families use pressure cookers in order to speed up the time it takes to cook meat.
a) Explain how a pressure cooker achieves this, in terms of pressures and boiling
points.
Vapor Pressure Curves – Homework WS #1
Use the graph shown below to answer the following questions.
1) What is the vapor pressure of the carbon disulfide at 30°C?
2) What is the boiling point of ethanol when the external pressure is 200 mmHg?
3) What is the normal boiling point of carbon disulfide?
4) What is the vapor pressure of heptane at 70°C?
5) What is the temperature if the vapor pressure of heptane is 450 mmHg?
6) Which substance on the graph has the weakest intermolecular forces of attraction?
Vapor Pressure Curves – Homework WS #2
Use the graph shown below to answer the following questions.
1)
What is the vapor pressure of chloroform at 50°C? _________________
2)
What is the boiling point of water when the external pressure is 30 kPa? _________________
3)
What is the normal boiling point of ethanol? _________________
4)
If ethanoic acid is boiling at 100°C, what is its external pressure? ___________________
5)
Comparing the curves, which substance (of the four given above) has the weakest IMFs?
6)
At an external pressure of 60 kPa, which substance would take the longest to heat to a boil?
Chapter 10: Phase Changes – Review Worksheet (Part 1)
A.
Matching: On the line at the left, write the term that best matches each description below:
vaporization
condensation
melting point
melting
phase change
sublimation
equilibrium vapor pressure
volatile
deposition
___________________________ 1) conversion of solid directly into a gas
___________________________ 2) opposite of vaporization
___________________________ 3) temperature at which solid and liquid phases exist in equilibrium.
___________________________ 4) conversion of a substance from one of the three states of matter
to another
___________________________ 5) change from a liquid to gas
___________________________ 6) pressure exerted by a constant number of gas molecules in
equilibrium with their liquid phase
___________________________ 7) description of a liquid that evaporates easily, with a low boiling
point and high vapor pressure
___________________________ 8) transformation of a gas directly into a solid
___________________________ 9) phase change from a solid to a liquid
B.
True/False: If the statement is true, write “true”. If it is false, change the underlined word or
words to make the statement true. Write your answer on the line provided.
___________________________ 1) The average kinetic energy of the particles in a liquid depends
upon the temperature.
___________________________ 2) Solids do not flow because the attractive forces between their
particles are weaker than those in liquids or gases
___________________________ 3) Dynamic equilibrium is reached when the rate of vaporization
exceeds the rate of condensation.
___________________________ 4) Condensing liquid water is the opposite of melting solid ice
___________________________ 5) All three states of matter can exist in equilibrium at the triple
point
C.
Fill in the diagram below with the appropriate phase changes.
D.
Fill in the phase diagram at right with
the three states of matter in the empty
ovals. Then state which phase changes
are be represented by letters A-F.
A. _____________________________
B. _____________________________
C. _____________________________
D. _____________________________
E. _____________________________
F. _____________________________
Ch. 10: Phase Changes – Review Worksheet (Part 2)
Phase Diagram for a Generic Substance:
Answer the following questions in relation to the phase diagram below.
1) What section represents the solid? _______
liquid ? _______
2) What letter represents the triple point? ________
gas? _______
critical point? ________
3) What state is this substance in at atmospheric pressure and room temperature (27ᵒC)?
4) What phase change occurs at 1 atm and 197.5ᵒC?
5) At 240ᵒC, what phase change would occur if the pressure increases from 4 atm to 10 atm?
6) At what temperature and pressure conditions do all three phases coexist?
7) At a constant temperature, what would you do to the pressure to cause this substance freeze
(liquid  solid)
Phase Diagram for Water:
Answer the following questions in relation to the phase diagram below.
1) What is the normal freezing point of water? ____________________
2) What is the normal boiling point of water? _____________________
3) What is the critical temperature and pressure of water?
4) Use line segments AB, BC, or BD to answer each if the following.
a) Which line segment represents melting?
_________
b) Which line segment represents deposition? _________
c) Which line segment represents evaporation? _________
d) Which line segment represents sublimation? _________
5) Identify the likely state of matter at each of the following conditions:
a) 80°C and 0.081 kPa
_____________________
b) 50°C and 10,000 kPa
_____________________
c) -100°C and 101.3 kPa
_____________________
Phase Diagram for Nitrogen (N2)
Answer the following questions in relation to the phase diagram below.
1) What is the normal melting point of nitrogen? ____________________
2) What is the normal boiling point of nitrogen? _____________________
3) At room temperature (27ᵒC) and atmospheric pressure, what state of matter is N2? ____________
4) In laboratories, nitrogen is purchased and delivered in its liquid state inside a pressurized canister.
a) Assuming that N2 was delivered at a pressure of 5 atm, what temperature must it have been?
b) When canister of liquid nitrogen is opened to standard laboratory conditions, what phase
change is expected to immediately occur?
c) Based on your knowledge of states of matter and melting/boiling points, would you consider
nitrogen (N2) to have strong or weak intermolecular attractive forces? Explain.