Chapter 3
Matter and
Energy
Matter

Matter is defined as anything that occupies
space and has mass–things you can see, touch,
taste, or smell.
States of Matter

Matter can be
classified as solid,
liquid, or gas based
on what properties it
exhibits.
States of Matter
State
Particle Spacing Shape
Volume
Compress
Solid
close
fixed
no
Liquid close
indefinite fixed
no
Gas
indefinite indefinite yes
far apart
fixed
Composition of Matter


Matter that is composed of only one kind of
atom or molecule is called a pure substance.
Matter that is composed of different kinds of
atoms or molecules is called a mixture.
Matter
Pure Substance
Constant Composition
Mixture
Variable Composition
Composition of Matter

Pure substance


Element—a substance that cannot be broken
down into other substances by chemical methods.
Compound—a substance composed of a given
combination of elements that can be broken down
into those elements by chemical methods.
Composition of Matter


Element: made of one
type of atom.
Compound: made of
one type of molecule, or
array of ions—more
than one type of atom.
Composition of Matter

Mixture


Mixtures that are uniform throughout are called
homogeneous. Also known as solutions.
Mixtures that have regions with different
characteristics are called heterogeneous.
Composition of Matter


Homogeneous—appears to be
one substance, all portions of
a sample have the same
composition and properties.
Heterogeneous—presence of
multiple substances can be
seen, portions of a sample
have different composition
and properties.
Composition of Matter

Mixtures can be separated
based on different physical
properties of the
components.
 Filtration
Composition of Matter

Distillation
Composition of Matter
Composition of Matter

Classify each of the following as a pure
substance (compound or element) or mixture
(homogeneous or heterogeneous).
1.
2.
3.
4.
5.
Pure water
Gasoline
Jar of jelly beans
Soil
Copper metal
Physical and Chemical Properties

The characteristics of a substance that
distinguish that substance are called its
properties.
Physical and Chemical Properties

Physical Properties are the characteristics of
matter that can be changed without changing
its composition.

Characteristics that are directly observable.
Physical and Chemical Properties

Chemical Properties are the characteristics
that determine how the composition of matter
changes as a result of contact with other
matter or the influence of energy.

Characteristics that describe the behavior of
matter.
Physical and Chemical Changes

Changes that alter the state
or appearance of the matter
without altering the
composition are called
physical changes.
Physical and Chemical Changes

Changes that alter the
composition of the matter
are called chemical
changes.
Physical and Chemical Properties
1.
Classify each of the following as a physical or chemical property.
a.
Ethyl alcohol boils at 78oC
b.
Sugar ferments to form ethyl alcohol
c.
Salt is stable at room temperature, it does not decompose
d.
36 g of salt will dissolve in 100 g of water
2.
Classify each of the following as a physical or chemical change.
a.
Sugar fermenting to form ethyl alcohol
b.
Dissolving of sugar in water
c.
Iron metal melting
d.
Iron combining with oxygen to form rust
Conservation of Mass

Matter is neither created nor destroyed in a
chemical reaction.
Conservation of Mass

15 g elemental
magnesium is burned in
the presence of oxygen;
25 g white magnesium
oxide result. What mass
oxygen was used up?
Energy


Energy is anything that
has the capacity to do
work.
All chemical and
physical changes result in
the matter changing
energy.
Energy


Potential energy is energy that is stored.
Kinetic energy is energy of motion, or energy
that is being transferred from one object to
another.
Energy

Energy can neither be created nor destroyed.
Energy

calorie (cal) is the amount of energy needed to raise
one gram of water by 1 °C.
Energy Conversion Factors
1 calorie (cal)
=
4.184 joules (J)
1 Calorie (Cal)
=
1000 calories (cal)
1 kilowatt-hour (kWh)
=
3.60 x 106 joules (J)
Energy and Chemical/Physical Change
Exothermic process—when a chemical or
physical change results in the release of
energy
Reactants
Potential energy

Surroundings
Amount
of energy
released
Products
reaction
Energy and Chemical/Physical Change
Endothermic process—when a chemical or
physical change requires the absorption of
energy
Products
Potential energy

Surroundings
Amount
of energy
absorbed
Reactants
reaction
Energy and Chemical/Physical Change

Classify each process as exothermic or
endothermic
1.
2.
3.
4.
5.
Your hand gets cold when you touch ice.
The ice gets warmer when you touch it.
Water boils in a kettle being heated on a stove.
Water vapor condenses on a cold pipe.
Ice cream melts.
Temperature

A measure of the random motions of the
components of a substance.


Fahrenheit, Celsius, Kelvin
Heat: a flow of energy between two objects
due to a temperature difference between the
objects.
Temperature
Temperature

Converting between scales
TK  T C + 273
TC 
1.
2.
T F
 32 
1.80
T C  TK  273
T F  1.80 T C  + 32
The normal body temperature for a dog is approximately
102oF. What is this equivalent to on the Kelvin
temperature scale?
If the outside temperature is 298 K, what would you
wear? What is this equivalent to on the Fahrenheit
temperature scale?
Heat Capacity

Energy (Heat) Required to Change the
Temperature of a Substance Depends On:



The amount of substance being heated (grams)
The temperature change (degrees).
The identity of the substance.
Heat Capacity


Heat capacity is the amount of heat a
substance must absorb to raise its temperature
by 1 °C.
Specific heat = heat capacity of 1 gram of the
substance.
Heat Capacity

Specific Heat
Capacities
Substance
Specific Heat
J/g°C
Aluminum
0.903
Carbon (dia)
0.508
Carbon (gra)
0.708
Copper
0.385
Gold
0.128
Iron
0.449
Lead
0.128
Silver
0.235
Ethanol
2.42
Water (l)
4.184
Water (s)
2.03
Water (g)
2.02
Summary of Topics: Chapter 3








Matter
Pure substances: compounds and elements
Mixtures: homogeneous and heterogeneous
Chemical, Physical properties
Chemical, Physical changes
Energy, exothermic and endothermic
Temperature conversions
Heat Capacity (qualitative)