V.%20Physical%20Behavior%20of%20Matter

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V. Physical Behavior of Matter
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Matter is classified as a pure substance or as a
mixture of substances. (3.1q)
Substances Substances Substances Mixtures
Elements Diatomic Elements Compounds

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The three phases of matter (solids, liquids, and
gases) have different properties. (3.1kk)
Solid Liquid Gas
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Properties of Solids

• Regular geometric pattern in the arrangement of
  the molecules called a crystal lattice
• Molecules are close together and vibrate in place
  
• Molecules do not move from place to place
• Solids are not compressible
• Definite shape and definite volume

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Properties of Liquids

• Molecules can move around (fluid)
• Molecules are farther apart than in a solid
• Liquids take the shape of their container
• Not compressible
• No definite shape but do have definite volume

The forces of attraction between the molecules
are weaker in a liquid than they are in a solid.
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Properties of Gases

• Molecules fill their container (spread out)
• Molecules are very far apart
• Molecules move in straight lines until they hit
  something (another molecule or wall of the
  container)
• No definite shape and no definite volume

The forces of attraction between the molecules
are very weak.
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Regents Question 08/02 16
Which statement correctly describes a sample of
gas confined in a sealed container? (1) It always
has a definite volume, and it takes the shape of
the container. (2) It takes the shape and the
volume of any container in which it is
confined. (3) It has a crystalline structure. (4)
It consists of particles arranged in a regular
geometric pattern.
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Regents Question 06/02 12
Which 5.0-milliliter sample of NH3 will take the
shape of and completely fill a closed
100.0-milliliter container? (1) NH3 (s) (3) NH3
(g) (2) NH3 (l) (4)NH3 (aq)
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Regents Question 06/03 16
In which material are the particles arranged in a
regular geometric pattern? (1) CO2 (g) (2)
NaCl(aq) (3) H2O(l) (4) C12H22O11 (s)
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A pure substance (element or compound) has a
constant composition and constant properties
throughout a given sample, and from sample to
sample. (3.1r)
All substances are homogeneous.
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Elements are substances that are composed of
atoms that have the same atomic number. Elements
cannot be broken down by chemical change. (3.1u)
There are more than 100 different
elements Elements are represented by chemical
symbols The first letter of the symbol is always
a capital letter the rest are lower case
A temporary symbol
Nitrogen
Neon
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Some elements are diatomic. They come in pairs
when not combined with other elements.

• H O N Cl Br I F

• Diatomic Elements
• Hydrogen
• Oxygen
• Nitrogen
• Chlorine
• Bromine
• Iodine
• Fluorine

Neon is a monatomic element
Nitrogen is a diatomic element
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Compounds are substances that are composed of two
or more different elements chemically combined.

• The elements in a compound are in fixed
  proportions
• A compound can only be decomposed by chemical
  means
• Compounds are represented by chemical formulas
• Compounds are electrically neutral

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Using particle diagrams to represent elements,
compounds and mixtures.
Compound
Element
Diatomic element
Mixture
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Regents Question 08/02 6
Which species represents a chemical compound? (1)
N2 (3) Na (2) NH4 (4) NaHCO3
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Compounds are made up of more than one type of
element. (Look for more than one capital letter.)
Compounds are electrically neutral.
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Regents Question 06/03 9
Which substance can be decomposed by a chemical
change? (1) Co (2) CO (3) Cr (4) Cu
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Mixtures are composed of two or more different
substances that can be separated by physical
means.
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Regents Question 06/02 43
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Regents Question 08/02 51
On a field trip, Student X and Student Y
collected two rock samples. Analysis revealed
that both rocks contained lead and sulfur. One
rock contained a certain percentage of lead and
sulfur by mass, and the other rock contained a
different percentage of lead and sulfur by mass.
Student X stated that the rocks contained two
different mixtures of lead and sulfur. Student Y
stated that the rocks contained two different
compounds of lead and sulfur. Their teacher
stated that both students could be correct. Draw
particle diagrams in each of the rock diagrams
provided in your answer booklet to show how
Student Xs and Student Ys explanations could
both be correct. Use the symbols in the key
provided in your answer booklet to sketch lead
and sulfur atoms.
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Regents Question 08/02 51 Answer
Draw particle diagrams in each of the rock
diagrams provided in your answer booklet to show
how Student Xs and Student Ys explanations
could both be correct. Use the symbols in the key
provided in your answer booklet to sketch lead
and sulfur atoms.
Student X
Student Y
Rock A Rock B
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When different substances are mixed together, a
homogeneous or heterogeneous mixture is formed.
(3.1s)
A homogeneous mixture is called a solution A
solution in which something is dissolved in water
is called an aqueous solution NaCl(aq) means that
sodium chloride (table salt) is dissolved in
water and is therefore a homogenous mixture. (aq)
stands for aqueous An alloy is a solution of
metals eg. brass, bronze
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Regents Question 06/03 15
Which of these terms refers to matter that could
be heterogeneous? (1) element (2) mixture (3)
compound (4) solution
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The proportions of components in a mixture can be
varied. Each component in a mixture retains its
original properties. (3.1t)
Two mixtures of Hydrogen (H2) and Neon (Ne)
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Differences in properties such as density,
particle size, molecular polarity, boiling point
and freezing point, and solubility permit
physical separation of the components of the
mixture. (3.1nn)
Chromatography, Filtration, Dissolving,
Distillation, Crystallization
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Regents Question 01/04 12
A bottle of rubbing alcohol contains both
2-propanol and water. These liquids can be
separated by the process of distillation because
the 2-propanol and water (1) have combined
chemically and retain their different boiling
points (2) have combined chemically and have the
same boiling point (3) have combined physically
and retain the different boiling points (4) have
combined physically and have the same boiling
point
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Density and polarity
Particle size
Boiling point
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A solution is a homogeneous mixture of a solute
dissolved in a solvent. The solubility of a
solute in a given amount of solvent is dependent
on the temperature, the pressure, and the
chemical natures of the solute and solvent.
(3.1oo)
Dissolved particles are too small to be trapped
by a filter
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Regents Question 08/02 7
Which mixture can be separated by using the
equipment shown? (1) NaCl(aq) and SiO2(s) (2)
NaCl(aq) and C6H12O6(aq) (3) CO2(aq) and
NaCl(aq) (4) CO2(aq) and C6H12O6(aq)
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(aq) stands for aqueous which means dissolved in
water.
Dissolved particles are too small to be trapped
by the filter.
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Solubility of a nonvolatile solute depends on
temperature.

• Solubility is the maximum amount of solute that a
  solvent can hold at a given temperature.
• An unsaturated solution is one in which the
  solvent can dissolve more solute
• A saturated solution is one in which the solvent
  has as much solute as it can hold
• A supersaturated solution is one in which there
  is more solute dissolved than a solvent can
  normally hold.
• Make a supersaturated solution by cooling a
  saturated solution
• Supersaturated solutions are unstable and will
  precipitate the excess solute when a seed crystal
  is added.
• As temperature increases, solubility of a solid
  increases.

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Table G shows the solubilities of some gases and
some solids at various temperatures when
dissolved in 100 grams of water.
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• A solution which is on the line is saturated
• A solution below the line is unsaturated
• A solution above the line is supersaturated

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Add a test crystal to see if a solution is
unsaturated, saturated or supersaturated.

• Unsaturated the test crystal dissolves
• Saturated the test crystal settles to the
  bottom
• Supersaturated a large amount of crystals
  precipitate from the solution

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Regents Question 06/02 40
According to Reference Table G, which solution is
saturated at 30C? (1) 12 grams of KClO3 in 100
grams of water (2) 12 grams of KClO3 in 200 grams
of water (3) 30 grams of NaCl in 100 grams of
water (4) 30 grams of NaCl in 200 grams of water
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The solubility of a gas depends on temperature
and pressure.

• As temperature increases, the solubility of a gas
  decreases
• As pressure increases, the solubility of a gas
  increases

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Which are gases?
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Regents Question 08/02 48
One hundred grams of water is saturated with
NH4Cl at 50C. According to Table G, if the
temperature is lowered to 10C, what is the total
amount of NH4Cl that will precipitate? (1) 5.0 g
(3) 30. g (2) 17 g (4) 50. g
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Regents Question 01/03 65-66
When cola, a type of soda pop, is manufactured,
CO2 (g) is dissolved in it. A capped bottle of
cola contains CO2 (g) under high pressure. When
the cap is removed, how does pressure affect the
solubility of the dissolved CO2 (g)? A glass of
cold cola is left to stand 5 minutes at room
temperature. How does temperature affect the
solubility of the CO2 (g)?
As the pressure decreases, the solubility
decreases.
As the temperature increases, the solubility
decreases.
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Oil and water are not miscible

• Like dissolves like (charged solutes dissolve in
  charged solvents, uncharged solutes dissolve in
  uncharged solvents)
• Nonpolar solutes dissolve in nonpolar solvents
• Polar solutes dissolve in polar solvents
• Ionic solutes dissolve in polar solvents

(Nonpolar)
(Polar)
Dry cleaners use a nonpolar solvent to get rid of
oil and grease Liquids that dissolve each other
are called miscible liquids.
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Regents Question 06/03 42
Hexane (C 6 H 14 ) and water do not form a
solution. Which statement explains this
phenomenon? (1) Hexane is polar and water is
nonpolar. (2) Hexane is ionic and water is
polar. (3) Hexane is nonpolar and water is
polar. (4) Hexane is nonpolar and water is ionic.
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Solubility Guidelines

• Not all substances are soluble in water
• Reference Table F lists solubility rules and
  exceptions to those rules.

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Soluble Not Soluble
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Regents Question 08/02 40
Which of the following compounds is least
soluble in water? (1) copper (II) chloride (2)
aluminum acetate (3) iron (III) hydroxide (4)
potassium sulfate
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Regents Question 06/03 14

• According to Table F, which of these salts is
  least soluble in water?
• LiCl
• (2) RbCl
• (3) FeCl2
• (4) PbCl2

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The concentration of a solution may be expressed
as molarity (M), percent by volume, percent by
mass, or parts per million (ppm). (3.1pp)
Molarity Percent by mass Parts per Million
M moles solute grams solute x 100 ppm grams solute x 1,000,000
Liters solution Grams solution Grams solution
Percent by volume
liters solute x 100 Liters solution
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Regents Question 06/02 42
What is the molarity of a solution that contains
0.50 mole of NaOH in 0.50 liter of solution? (1)
1.0 M (3) 0.25 M (2) 2.0 M (4) 0.50 M
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Regents Question 08/02 36
How many moles of solute are contained in 200
milliliters of a 1 M solution? (1) 1 (3)
0.8 (2) 0.2 (4) 200
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Regents Question 08/02 49
What is the total number of grams of NaI(s)
needed to make 1.0 liter of a 0.010 M
solution? (1) 0.015 (3) 1.5 (2) 0.15 (4) 15
þ
X 0.010 moles
0.010 moles x 149.9 g/mole
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Regents Question 01/03 40
Solubility data for four different salts in water
at 60C are shown in the table below. Which salt
is most soluble at 60C? (1) A (2) B (3)
C (4) D Salt Solubility in Water at 60
C A - 10 grams /50 grams H2O B - 20 grams /60
grams H2O C - 30 grams /120 grams H2O D - 40
grams/80 grams H2O
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Regents Question 01/04 56-58
A student uses 200 grams of water at a
temperature of 60C to prepare a saturated
solution of potassium chloride, KCl. Identify the
solute in this solution. According to Reference
Table G, how many grams of KCl must be used to
create this saturated solution? This solution
is cooled to 10C and the excess KCl precipitates
(settles out). The resulting solution is
saturated at 10C. How many grams of KCl
precipitated out of the original solution?
KCl
90 g
Hint 200 g of water was used table G is for
100 g of water
60 g
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The addition of a nonvolatile solute to a solvent
causes the boiling point of the solvent to
increase and the freezing point of the solvent to
decrease. The greater the concentration of
particles, the greater the effect. (3.1qq)
Solute Moles of particles per mole of solute
C6H12O6 1 (Non-electrolytes do not separate into ions)
NaCl 2 (1-Na and 1 Cl-)
CaF2 3 (1-Ca2 and 2 F-)
H2SO4 3 (2-H and 1 SO42-)
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Regents Question 06/03 23
At standard pressure when NaCl is added to water,
the solution will have a (1) higher freezing
point and a lower boiling point than water (2)
higher freezing point and a higher boiling point
than water (3) lower freezing point and a higher
boiling point than water (4) lower freezing point
and a lower boiling point than water
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Regents Question 01/04 13
Compared to pure water, an aqueous solution of
calcium chloride has a (1) higher boiling point
and higher freezing point (2) higher boiling
point and lower freezing point (3) lower boiling
point and higher freezing point (4) lower boiling
point and lower freezing point
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Energy can exist in different forms, such as
chemical, electrical, electromagnetic, thermal,
mechanical, and nuclear. (4.1a)
Kinetic energy the energy of motion Potential
energy the energy of position (stored energy)
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The amount of thermal energy contained in the
molecules depends on how fast they are moving and
how many molecules there are.

• The total kinetic energy of all the molecules
  combined is called thermal energy
• Thermal energy is a result of the Kinetic Energy
  of the molecules motion (molecules are always
  moving.)
• Which can melt more ice a small cup of hot water
  or a swimming pool of cold water?

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Heat is a transfer of energy (usually thermal
energy) from a body of higher temperature to a
body of lower temperature. Thermal energy is the
energy associated with the random motion of atoms
and molecules. (4.2a)
The Law of the Conservation of Energy states that
energy can neither be created nor destroyed.
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Heat is transferred to different materials at
different rates.

• The specific heat capacity (C) determines the
  rate at which heat will be absorbed.
• The specific heat capacity for water is 4.18J/g
• The quantity of heat absorbed (Q) can be
  calculated by QmC?T
• mmass ?Tchange in temperature

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Temperature is a measurement of the average
kinetic energy of the particles in a sample of
material. Temperature is not a form of energy.
(4.2b)
Two temperature scales used in chemistry are
Celsius and Absolute The unit of temperature in
the Celsius scale is the degree (ºC) The unit of
temperature on the Absolute scale is the Kelvin
(K)
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Regents Question 06/02 16
Which change in the temperature of a 1-gram
sample of water would cause the greatest increase
in the average kinetic energy of its
molecules? (1) 1C to 10C (3) 50C to 60C (2)
10C to 1C (4) 60C to 50C
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To convert between absolute and Celsius
temperature scales use KºC273
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The concept of an ideal gas is a model to explain
the behavior of gases. A real gas is most like an
ideal gas when the real gas is at low pressure
and high temperature. (3.4a)
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Kinetic molecular theory (KMT) for an ideal gas
states that all gas particles (3.4b)

• 1. are in random, constant, straight-line motion.
• 2. are separated by great distances relative to
  their size the volume of the gas particles is
  considered negligible.
• 3. have no attractive forces between them.
• 4. have collisions that may result in the
  transfer of energy between gas particles, but the
  total energy of the system remains constant.

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Real Gases

• Molecules do take up space
• Molecules do attract each other
• Energy is lost during collisions
• Under conditions of high temperature and low
  pressure, real gases behave more like ideal gases
• Small molecules take up little space and have
  weaker forces of attraction and are closer to an
  ideal gas
• Hydrogen and helium are closest to being
• ideal gases

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Collision theory states that a reaction is most
likely to occur if reactant particles collide
with the proper energy and orientation. (3.4d)
Anything that will increase the number of
effective collisions will increase the rate at
which the reaction will occur
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Factors that affect the rate of a chemical
reaction

• Temperature higher temp faster rate
• Molecules collide more often and with more energy
• Concentration higher conc faster rate
• Molecules collide more often
• Increasing the pressure on a gas increases the
  concentration of molecules faster rate
• Surface are smaller particles faster rate
• More site for the collisions to occur
• Catalyst changes the mechanism to lower the
  activation energy

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Regents Question 08/02 37
Increasing the temperature increases the rate of
a reaction by (1) lowering the activation
energy (2) increasing the activation energy (3)
lowering the frequency of effective collisions
between reacting molecules (4) increasing the
frequency of effective collisions between
reacting molecules
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Kinetic molecular theory describes the
relationships of pressure, volume, temperature,
velocity, and frequency and force of collisions
among gas molecules. (3.4c)
P1V1 P2V2
T2 T2
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Ideal Gas Laws

• Boyles Law
• Indirect Relationship between pressure and volume
• Temperature remains constant
• PxV constant

• Charles law
• Direct relationship between volume and
  temperature
• Pressure remains constant
• V/T constant
• Temperature must be Absolute temperature (Kelvins)

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Graphing the gas laws
As absolute temperature increases, pressure
increases at constant volume
Pressure
Temperature
As absolute temperature increases, volume
increases at constant pressure
Volume
Temperature
As pressure increases, volume decreases at
constant temperature
Volume
Pressure
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Regents Question 06/02 14
Which graph shows the pressure-temperature
relationship expected for an ideal gas?
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Equal volumes of different gases at the same
temperature and pressure contain an equal number
of particles. (3.4e)
Avogadros Hypothesis
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Regents Question 06/02 15
At the same temperature and pressure, which
sample contains the same number of moles of
particles as 1 liter of O2 (g)? (1) 1 L
Ne(g) (3) 0.5 L SO2 (g) (2) 2 L N2 (g) (4) 1 L
H2O(l)
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The concepts of kinetic and potential energy can
be used to explain physical processes that
include fusion (melting), solidification
(freezing), vaporization (boiling, evaporation),
condensation, sublimation, and deposition. (4.2c)
Add energy (endothermic) subliming
melting boiling
SOLID LIQUID GAS
Remove energy (exothermic) freezing depositing condensing

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Regents Question 06/03 17
Which change is exothermic? (1) freezing of
water (2) melting of iron (3) vaporization of
ethanol (4) sublimation of iodine
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A change in phase is a change in Potential
Energy, not Kinetic Energy
Boiling Point
Potential energy changes so temperature doesnt
Melting Point
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Energy and phase changes

• AB - solid warms up (KE inc/PE constant)
• BC- solid melts (KE constant/PE inc)
• CD liquid warms up (KE inc/PE constant)
• DE- liquid boils (KE constant/PE inc)

• EF gas warms (KE inc/PE constant)

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Regents Question 06/02 28
As ice melts at standard pressure, its
temperature remains at 0C until it has
completely melted. Its potential energy (1)
decreases (2) increases (3) remains the same
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Regents Question 08/02 54
A sample of water is heated from a liquid at 40C
to a gas at 110C. The graph of the heating curve
is shown in your answer booklet. a On the
heating curve diagram provided in your answer
booklet, label each of the following
regions Liquid, only Gas, only Phase change
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Regents Question contd
b For section QR of the graph, state what is
happening to the water molecules as heat is
added. c For section RS of the graph, state what
is happening to the water molecules as heat is
added.
They move faster, their temperature increases.
Their intermolecular bonds are breaking, their
potential energy is increasing.
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Regents Question 01/02 47
What is the melting point of this substance? (1)
30C (3) 90C (2) 55C (4) 120C
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The quantity of energy absorbed or released
during a phase change can be calculated using the
Heat of Fusion or Heat of Vaporization

• Melting (fusion) or freezing (solidification)
• QmHf where Hf is the heat of fusion
• (for water 333.6 J/g)
• Boiling (vaporization) or condensing
• QmHv where Hv is the heat of vaporization
• (for water 2259 J/g)

Hf and Hv are given to Table B m is the mass
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Regents Question 08/02 24
In which equation does the term heat represent
heat of fusion? (1) NaCl(s) heat ? NaCl(l) (2)
NaOH(aq) HCl(aq) ? NaCl(aq) H2O(l) heat (3)
H2O(l) heat ? H2O(g) (4) H2O(l) HCl(g)
?H3O(aq) Cl (aq) heat
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Fusion refers to melting.
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Melting Point

• The temperature at which a liquid and a solid are
  in equilibrium
• The melting point for ice is 0ºC
• The melting point of a substance is the same as
  its freezing point

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Regents Question 08/02 5
Given the equation H2O(s) H2O(l) At
which temperature will equilibrium exist when the
atmospheric pressure is 1 atm? (1) 0 K (3) 273
K (2) 100 K (4) 373 K
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KC 273
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Regents Question 08/02 18
The solid and liquid phases of water can exist in
a state of equilibrium at 1 atmosphere of
pressure and a temperature of (1) 0C (3)
273C (2) 100C (4) 373C
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Regents Question 06/03 41
The freezing point of bromine is (1) 539C (2)
539C (3) 7C (4) 7C
See Table S Melting point is the same as freezing
point Convert K to C (KC273)
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86
A physical change results in the rearrangement of
existing particles in a substance. A chemical
change results in the formation of different
substances with changed properties. (3.2a)

• Physical Changes
• Changes in phase
• Melting
• Boiling
• Subliming
• Dissolving

• Chemical Changes
• Any chemical reaction
• Synthesis
• Decomposion
• Single Replacment
• Double Replacement
• Combustion (burning)

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Regents Question 06/03 18
Which type of change must occur to form a
compound? (1) chemical (2) physical (3)
Nuclear (4) phase
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88
Chemical and physical changes can be exothermic
or endothermic. (4.1b)

• Exothermic
• Potential energy decreases
• Releases energy
• ?H is negative
• Energy is on the right
• 2H2 O2 2H2O energy

• Endothermic
• Potential energy increases
• Absorbs energy
• ?H is positive
• Energy is on the left
• 2H2O energy 2H2 O2

PE
PE
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Regents Question 06/02 64-66

• A hot pack contains chemicals that can be
  activated to produce heat. A cold pack contains
  chemicals that feel cold when activated.
• Based on energy flow, state the type of chemical
  change that occurs in a hot pack.
• A cold pack is placed on an injured leg. Indicate
  the direction of the flow of energy between the
  leg and the cold pack.
• What is the Law of Conservation of Energy?
  Describe how the Law of Conservation of Energy
  applies to the chemical reaction that occurs in
  the hot pack.

Exothermic
From the leg to the cold pack (Hot to Cold)
Energy cannot be created nor destroyed. It can
only be changed from one form to another. The
heat produced in the hot pack was stored in the
chemical bonds.
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Regents Question 08/02 41
According to Table I, which potential energy
diagram best represents the reaction that forms
H2O(l) from its elements?
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91
Activation Energy (Ea) is the energy needed to
get a reaction started (reach the activated
complex).
92
Enthalpy (?H) The heat of reaction

• ?HPE products PE reactants
• The value for ?H is the same in the forward and
  the reverse reaction. Only the sign is changed.
• Measured in kJ (kilojoules)
• ?H Endothermic Energy absorbed
• - ?H Exothermic Energy released
• The large the value of ?H, the more energy
  absorbed or released
• Reference Table I gives ?H for many reactions

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Regents Question 08/02 14
Given the reaction CH4 (g) 2 O2 (g) ? 2 H2O(g)
CO2 (g) What is the overall result when CH4 (g)
burns according to this reaction? (1) Energy is
absorbed and ?H is negative. (2) Energy is
absorbed and ? H is positive. (3) Energy is
released and ? H is negative. (4) Energy is
released and ? H is positive.
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94
Regents Question 08/02 34
According to Table I, which salt releases energy
as it dissolves? (1) KNO3 (3) NH4NO3 (2) LiBr
(4) NaCl
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95
Regents Question 08/02 50
Given the reaction 2 H2 (g) O2 (g) ? 2 H2O(l)
571.6 kJ What is the approximate ?H for the
formation of 1 mole of H2O(l)? (1) 285.8 kJ
(3) 571.6 kJ (2) 285.8 kJ (4) 571.6 kJ
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96
A catalyst lowers the activation energy to speed
up a reaction
Activated Complex With Catalyst
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Regents Question 06/02 55-56

• Given the reaction
• A B ? C
• Does the diagram illustrate an exothermic or an
  endothermic reaction?

Endothermic

• State one reason, in terms of energy, to support
  your answer.
• On the diagram provided in your answer booklet,
  draw a dashed line to indicate a potential energy
  curve for the reaction if a catalyst is added.

The potential energy of the products is higher
than the reactants, Energy is absorbed.
98
The structure and arrangement of particles and
their interactions determine the physical state
of a substance at a given temperature and
pressure. (3.1jj)
Solid Liquid Gas
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Intermolecular forces created by the unequal
distribution of charge result in varying degrees
of attraction between molecules. Hydrogen bonding
is an example of a strong intermolecular force.
(5.2m)

Dipole-Dipole attraction between polar molecules
100
Hydrogen bonds occur when hydrogen is bonded to a
small, highly electronegative atom.

• N, O and F can have hydrogen bonds when hydrogen
  is bonded to it.
• Account for the unusual properties of water
• High boiling point, surface tension, six sided
  snowflake

101
Physical properties of substances can be
explained in terms of chemical bonds and
intermolecular forces.

• Ionic bonds are strong
• Hydrogen bonds are strong intermolecular forces
• Polar molecules exhibit attraction between the
  and sides of their molecules
• Bonds between nonpolar molecules are weak. The
  more protons in the molecule, the stronger these
  forces.

102
Regents Question 06/02 13
The strongest forces of attraction occur
between molecules of (1) HCl (3) HBr (2) HF
(4) HI
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103
These properties include conductivity,
malleability, solubility, hardness, melting
point, and boiling point. (5.2n)

• The stronger the intermolecular forces, the
  higher the boiling point and melting point.
• The stronger the intermolecular forces, the lower
  the vapor pressure.
• See Table H

104
Table H the vapor pressure of four liquids at
various temperatures.
As temp inc, vapor pressure inc.
105
Regents Question 06/03 40

• According to Reference Table H, what is the vapor
  pressure of propanone at 45C?
• 22 kPa
• 33 kPa
• 70. kPa
• (4) 98 kPa

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106
A liquid will boil when its vapor pressure equals
the atmospheric pressure.

• Raising the temperature will increase the vapor
  pressure of the liquid
• Lowering the atmospheric pressure will lower the
  boiling point
• On top of a high mountain, water boils at a
  temperature below 100?C

107
Standard pressure is 101.3 kilopascals (kPa) or
1 atmoshpere (atm)
The normal boiling point occurs when the
atmospheric pressure is 101.3 kPa (standard
pressure)
The normal boiling point of ethanol is 80ºC.
108
Regents Question 08/02 28
As the pressure on the surface of a liquid
decreases, the temperature at which the liquid
will boil (1) decreases (2) increases (3) remains
the same
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109
Regents Question 08/02 30
As the temperature of a liquid increases, its
vapor pressure (1) decreases (2) increases (3)
remains the same
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110
Regents Question 08/02 44
The vapor pressure of a liquid is 0.92 atm at
60C. The normal boiling point of the liquid
could be (1) 35C (3) 55C (2) 45C (4) 65C
þ
The normal boiling point is the temperature at
which a liquid boils when the atmospheric
pressure is standard pressure (1 atm or 101.3 kPa)
111
Regents Question 01/03 68
What is the vapor pressure of liquid A at 70C?
Your answer must include correct units.
700 mm Hg
112
Regents Question 01/03 69
At what temperature does liquid B have the same
vapor pressure as liquid A at 70C? Your answer
must include correct units.
113C
113
Regents Question 01/03 70
Which liquid will evaporate more rapidly? Explain
your answer in terms of intermolecular forces.
Liquid A will evaporate more rapidly because, at
any temperature, it has the higher vapor
pressure.