Download Chemistry: Matter and Change

Matter - Properties and Change
CHAPTER
3
Table Of Contents
Section 3.1
Properties of Matter
Section 3.2
Changes in Matter
Section 3.3
Mixtures of Matter
Section 3.4
Elements and Compounds
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SECTION
3
Properties of Matter
.1
• Identify the characteristics of a substance.
• Distinguish between physical and chemical
properties.
• Differentiate among the physical states of matter.
density: a ratio that compares the mass of an
object to its volume
SECTION
Properties of Matter
3
.1
states of matter
physical property
solid
extensive property
liquid
intensive property
gas
chemical property
vapor
Most common substances exist as solids,
liquids, and gases, which have diverse
physical and chemical properties.
SECTION
Properties of Matter
3
.1
Substances
• A substance, also known as a chemical, is
matter that has a definite composition.
• Matter is anything that has mass and takes up
space.
• Matter is everything around us.
• Matter with a uniform and unchanging
composition is a substance.
SECTION
3
Properties of Matter
.1
States of Matter
• The physical forms of matter, either solid, liquid,
or gas, are called the states of matter.
• Solids are a form of matter that
have their own definite shape and
volume.
• Liquids are a form of matter that
have a definite volume but take the
shape of the container.
SECTION
3
Properties of Matter
.1
States of Matter (cont.)
• Gases have no definite shape or
volume. They expand to fill their
container.
• Vapor refers to the gaseous state of a
substance that is a solid or liquid at room
temperature.
• Plasma - It does not occur naturally on earth
except in the form of lightning bolts. Similar to
gas in which a certain portion of the particles
are ionized.
SECTION
3
Properties of Matter
.1
Physical Properties of Matter
• A physical property is a characteristic that can
be observed or measured without changing the
sample’s composition.
SECTION
3
Properties of Matter
.1
Physical Properties of Matter (cont.)
• Extensive properties, are dependent on
the amount of substance present.
• Intensive properties, are dependent on the
what the substance is not how much there is.
Extensive Properties Intensive Properties
SECTION
3
Properties of Matter
.1
Chemical Properties of Matter
• The ability of a substance to combine with
or change into one or more other
substances is called a chemical property.
– Iron forming rust
– Copper turning green in the air
SECTION
3
Properties of Matter
.1
Observing Properties of Matter
• A substance can change form–an important
concept in chemistry.
• Both physical and chemical properties can
change with specific environmental conditions,
such as temperature and pressure.
SECTION
3
Section Check
.1
Density is what kind of property?
A. atomic
B. intensive
C. extensive
D. dependent
SECTION
3
Section Check
.1
What defines a gas?
A. Gases have a definite volume and shape.
B. Gases have a definite volume but take the
shape of their container.
C. Gases have no definite volume or shape.
D. Gases have a definite shape but no definite
volume.
Changes in Matter
SECTION
3
Changes in Matter
.2
• Define physical change and list several common
physical changes.
• Define chemical change and list several indications
that a chemical change has taken place.
• Apply the law of conservation of mass to chemical
reactions.
observation: orderly, direct information gathering about a
phenomenon
SECTION
Changes in Matter
3
.2
physical change
phase change
chemical change
law of conservation of mass
Matter can undergo physical and chemical
changes.
SECTION
3
Changes in Matter
.2
Physical Changes
• A change that alters a substance without
changing its composition is known as a
physical change.
• A phase change is a transition of matter from
one state to another.
• Boiling, freezing, melting, and condensing all
describe phase changes in chemistry.
SECTION
3
Changes in Matter
.2
Chemical Changes
• A change that involves one or more
substances turning into new substances is
called a chemical change.
• Decomposing, rusting, exploding, burning, or
oxidizing are all terms that describe chemical
changes.
SECTION
3
Changes in Matter
.2
Conservation of Mass
• The law of conservation of mass states that
mass is neither created nor destroyed in a
chemical reaction, it is conserved.
• The mass of the reactants equals the mass of
the products.
massreactants = massproducts
SECTION
3
Section Check
.2
When one substances turns into another,
what kind of change has taken place?
A. chemical reaction
B. physical reaction
C. extensive reaction
D. nuclear reaction
SECTION
3
Section Check
.2
The law of conservation of mass states
that:
A. Matter can be created and destroyed.
B. Matter can be created but not destroyed.
C. The products of a reaction always have a
greater mass than the reactants.
D. The products of a reaction must have the same
mass as the reactants.
Mixtures of Matter
SECTION
3
Mixtures of Matter
.3
• Contrast mixtures and substances.
• Classify mixtures as homogeneous or
heterogeneous.
• List and describe several techniques used to
separate mixtures.
substance: a form of matter that has a uniform and
unchanging composition; also known as a pure
substance
SECTION
3
Mixtures of Matter
.3
mixture
distillation
heterogeneous mixture
crystallization
homogeneous mixture
sublimation
solution
chromatography
filtration
Most everyday matter occurs as
mixtures—combinations of two or more
substances.
SECTION
3
Mixtures of Matter
.3
Mixtures
• A mixture is a combination of two or more pure
substances in which each pure substance
retains its individual chemical properties.
• A heterogeneous mixture is a mixture where
the individual substances remain distinct.
• Two types – colloid and suspension
SECTION
Mixtures of Matter
3
.3
Mixtures (cont.)
• A homogenous mixture is a mixture where
the composition is constant throughout.
• Homogeneous mixtures are also called
solutions.
SECTION
3
.3
Mixtures (cont.)
Mixtures of Matter
SECTION
3
Mixtures of Matter
.3
Separating Mixtures
• Filtration is a technique that uses a porous
barrier to separate a solid from a liquid in a
heterogeneous mixture.
• Distillation is a separation technique for
homogeneous mixtures that is based on the
differences in boiling points of substances.
• Crystallization is a separation technique for
homogenous mixtures that results in the
formation of pure solid particles from a solution
containing the dissolved substance.
SECTION
3
Mixtures of Matter
.3
Separating Mixtures (cont.)
• Sublimation is the process of a solid changing
directly to a gas, which can be used to separate
mixtures of solids when one sublimates and the
other does not.
• Chromatography is a technique that separates
the components of a mixture on the basis of
tendency of each to travel across the surface of
another material.
SECTION
3
Section Check
.3
Which is NOT a technique for separating
a homogenous mixture?
A. crystallization
B. distillation
C. filtration
D. chromatography
SECTION
3
Section Check
.3
Which of the following is a heterogeneous
mixture?
A. seawater
B. silver mercury amalgam
C. atmosphere
D. salad dressing
Elements and Compounds
SECTION
3
Elements and Compounds
.4
• Distinguish between elements and compounds.
• Describe the organization of elements in the periodic
table.
• Explain how all compounds obey the laws of definite
and multiple proportions.
proportion: the relation of one part to another or to the
whole with respect to quantity
SECTION
Elements and Compounds
3
.4
element
law of definite proportions
periodic table
percent by mass
compound
law of multiple proportions
A compound is a combination of two or
more elements.
SECTION
3
Elements and Compounds
.4
Elements
• An element is a pure substance that cannot be
separated into simpler substances by physical
or chemical means.
• 92 elements occur naturally on Earth.
• Each element has a unique name and a one,
two, or three-letter symbol.
SECTION
3
Elements and Compounds
.4
Elements (cont.)
• The periodic table organizes the elements into
a grid of horizontal rows called periods and
vertical columns called groups.
• Elements in the same group have similar
chemical and physical properties.
• The table is called periodic because the pattern
of similar properties repeats from period to
period.
SECTION
3
Elements and Compounds
.4
Compounds (cont.)
• A compound is a made up of two or more
elements combined chemically.
• Most of the matter in the universe exists as
compounds.
• Table salt, NaCl, and water, H2O, are
compounds.
• Unlike elements, compounds can be broken
into smaller components by chemical means.
SECTION
3
Elements and Compounds
.4
Compounds (cont.)
• Separating a
compounds into its
elements often requires
external energy, such
as heat or electricity.
• This figure shows
electrolysis of water to
form hydrogen and
oxygen gas.
SECTION
3
Elements and Compounds
.4
Compounds (cont.)
• The properties of a compound are different
from its component elements.
Comparison of Mixture and a Compound
Mixture
Compound
Properties of the components
are not changed
Properties of the elements
are changed
No heat needed to make a mixture
Heat is usually needed to make a
compound
A mixture can be fairly easily
separated
Difficult to separate into its
elements
Variable composition
Fixed composition - chemical
formula can be written
SECTION
3
Elements and Compounds
.4
Law of Definite Proportions
• The law of definite proportions states
that a compound is always composed of
the same elements in the same proportion
by mass, no matter how large or small the
sample.
–Ex. Water is always composed of 2 Hydrogen to
1 Oxygen
SECTION
3
Elements and Compounds
.4
Law of Definite Proportions (cont.)
• The relative amounts are expressed as
percent by mass, the ratio of the mass of
each element to the total mass of the
compound expressed as a percentage.
SECTION
3
Elements and Compounds
.4
Law of Definite Proportions (cont.)
• This table demonstrates that the percentages of
elements in sucrose remain the same despite
differences in sample amount.
SECTION
3
Elements and Compounds
.4
Law of Multiple Proportions
• The law of multiple proportions states that if
elements form more than one compound, those
compounds will have compositions that are
small, whole number multiples of each other Ex.
Fe2O3 and FeO
– Ex. Peroxide, H2O2, and water, H2O.
– Different compounds formed from the same elements.
– Hydrogen mass the same in both compounds but oxygen
mass is a 2:1 ratio in peroxide to water.
The law of multiple proportions states that if the
elements X and Y form two compounds, the
different masses of Y that combine with a fixed
mass of X can be expressed as a ratio of small
whole numbers.
Mass ratio compound I
Mass ratio compound II
SECTION
3
Elements and Compounds
.4
Law of Multiple Proportions (cont.)
SECTION
3
Section Check
.4
What is a period on the periodic table of
the elements?
A. a vertical columns
B. even numbered elements only
C. horizontal rows
D. the last vertical column only
SECTION
3
Section Check
.4
An element is a substance that cannot be
A. divided into simpler substances by physical
or chemical means.
B. combined to form a mixture.
C. combined to form an element.
D. different phases.
CHAPTER
3
Matter—Properties and Changes
Resources
Chemistry Online
Study Guide
Chapter Assessment
Standardized Test Practice
SECTION
Properties of Matter
3
.1
Study Guide
Key Concepts
• The three common states of matter are solid, liquid,
and gas.
• Physical properties can be observed without altering a
substance’s composition.
• Chemical properties describe a substance’s ability to
combine with or change into one or more new
substances.
• External conditions can affect both physical and
chemical properties.
SECTION
Changes in Matter
3
.2
Study Guide
Key Concepts
• A physical change alters the physical properties of a
substance without changing its composition.
• A chemical change, also known as a chemical reaction,
involves a change in a substance’s composition.
• In a chemical reaction, reactants form products.
• The law of conservation of mass states that mass is
neither created nor destroyed during a chemical reaction;
it is conserved.
massreactants = massproducts
SECTION
Mixtures of Matter
3
.3
Study Guide
Key Concepts
• A mixture is a physical blend of two or more pure
substances in any proportion.
• Solutions are homogeneous mixtures.
• Mixtures can be separated by physical means.
Common separation techniques include filtration,
distillation, crystallization, sublimation, and
chromatography.
SECTION
Elements and Compounds
3
.4
Study Guide
Key Concepts
• Elements cannot be broken down into simpler
substances by physical or chemical means.
• Elements are organized in the periodic table of the
elements.
• Compounds are chemical combinations of two or more
elements and their properties differ from the properties
of their component elements.
SECTION
Elements and Compounds
3
.4
Study Guide
Key Concepts
• The law of definite proportions states that a
compound is always composed of the same
elements in the same proportions.
• The law of multiple proportions states that if elements
form more than one compound, those compounds will
have compositions that are whole-number multiples of
each other.
CHAPTER
3
Matter—Properties and Changes
Chapter Assessment
Which of the following is NOT a physical
property of water?
A. Ice melts at 0°C.
B. Water boils at 100.
C. Water reacts violently with pure sodium.
D. Water is a liquid at room temperature.
CHAPTER
3
Matter—Properties and Changes
Chapter Assessment
28.0 grams of nitrogen gas reacts
completely with 6.0 grams of hydrogen to
form 34.0 grams of ammonia. What does
this demonstrate?
A. the law of conservation of energy
B. sublimation
C. distillation
D. the law of conservation of mass
CHAPTER
3
Matter—Properties and Changes
Chapter Assessment
What is the best way to separate salt
dissolved in water?
A. sublimation
B. crystallization
C. freezing
D. filtration
CHAPTER
3
Matter—Properties and Changes
Chapter Assessment
Two or more elements chemically joined
form what?
A. substance
B. heterogeneous mixture
C. homogenous solution
D. compound
CHAPTER
3
Matter—Properties and Changes
Chapter Assessment
What is the ratio of oxygen to carbon in
carbon dioxide (CO2)?
A. 2:1
B. 1:2
C. 1:1
D. 1:3
CHAPTER
3
Matter—Properties and Changes
Standardized Test Practice
Which is NOT a chemical reaction?
A. a car rusting
B. dissolving sugar in water
C. wood burning
D. a banana ripening
CHAPTER
3
Matter—Properties and Changes
Standardized Test Practice
Which describes a substance that is in the
liquid state?
A. It has a definite shape.
B. It has no definite volume.
C. It can be compressed into a
smaller volume.
D. It has a definite volume.
CHAPTER
3
Matter—Properties and Changes
Standardized Test Practice
Elements in the same group are likely to
have similar ____.
A. physical properties
B. densities
C. chemical properties
D. melting points
CHAPTER
3
Matter—Properties and Changes
Standardized Test Practice
Filtration is an easy way to separate
what?
A. heterogeneous mixture
B. homogeneous mixture
C. compounds
D. solutions
CHAPTER
3
Matter—Properties and Changes
Standardized Test Practice
Compounds can be broken into their
component elements by which of the
following?
A. crystallization
B. distillation
C. filtration
D. chemical reaction
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