2.1 Properties of Matter > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights...

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2.1 Properties of Matter 2.1 Properties of Matter >>

Chapter 2Matter and Change

2.1 Properties of Matter

2.2 Mixtures2.3 Elements and Compounds2.4 Chemical Reactions

In this lesson, you will learn how properties can be used to classify and identify matter.

CHEMISTRY & YOUCHEMISTRY & YOU

Why are windows made of glass?

Describing Matter

Why do all samples of a substance have the same properties?

Describing MatterDescribing Matter

What you observe when you look at a particular sample of matter is its properties.

• Is a solid shiny or dull?• Does a liquid flow quickly or slowly?• Is a gas odorless, or does it have a smell?

What is Matter?

What are Properties?

Matter is any thing that has mass and takes up space. (even air!) DEMO

Matter can be described by properties.

How can matter be described?

Distinguishing qualities or attributes of a sample of matter

The mass of an object is a measure of the amount of matter the object contains.

A Property Example

The mass of a basketball is greater than the mass of a golf ball.

The volume of an object is a measure of the space occupied by the object.

• The volume of a basketball is greater than the volume of a golf ball.

Another Property Example

For example, leather balls are suitable for indoor play but not outdoor play.

• Leather balls absorb water and dirt more than rubber balls do.

What about what the substance’s “insides”?

• Absorbency

• Conductivity

• Malleability

• Color

• Odor

• State of Matter

More examples of properties

• Reactivity

• Flammability

• Toxicity

• Oxidizing

• Radioactivity

• Combustibility

• A physical property is a quality or condition of a substance that can be observed or measured without changing the substance’s composition.

• A chemical property is a quality or condition that gives matter the ability to undergo a change that alters its composition

Two different types of properties

• Absorbency

• Conductivity

• Malleability

• Color

• Odor

• State of Matter

More examples of properties

• Reactivity

• Flammability

• Toxicity

• Oxidizing

• Radioactivity

• Combustibility

Physical properties Chemical properties

Every sample of a given substance has identical properties because every sample has the same composition.

Identifying a Substance

Glass is often used to make windows, while copper is often used in electrical wires. What properties of glass make it a desirable material to use for windows?

Glass is transparent, so it can be seen through; hard, so it stays in place within window frames; and heat resistant, so it helps prevent the transfer of heat between outside and inside.

You want to compile a list of properties of any substance, what could you observe or measure?

List at least 5 different properties and label as Physical or Chemical

States of Matter

What are three states of matter?

States of MatterStates of Matter

Three states of matter are solid, liquid, and gas.

Kinetic Art- Pearson

A substance is in a state in which it takes the shape of its container. What state or states could it be in?

The substance could be either a liquid or a gas, as each takes the shape of its container.

Physical properties can help chemists identify substances.

• For example, a colorless substance that was found to boil at 100˚C and melt at 0˚C would likely be water.

• A colorless substance that boiled at 78˚C and melted at –117˚C would definitely not be water. It would likely be ethanol.

Identifying a Substance

Physical Properties of Some Substances

Substance State Color Melting point (°C) Boiling point (°C)

Neon Gas Colorless –249 –246

Oxygen Gas Colorless –218 –183

Chlorine Gas Greenish-yellow –101 –34

Ethanol Liquid Colorless –117 78

Mercury Liquid Silvery-white –39 357

Bromine Liquid Reddish-brown –7 59

Water Liquid Colorless 0 100

Sulfur Solid Yellow 115 445

Sodium chloride Solid White 801 1413

Gold Solid Yellow 1064 2856

Copper Solid Reddish-yellow 1084 2562

Interpret DataInterpret Data

This table lists physical properties for some substances.

• The states of the substances are given at room temperature.

In this lesson, you will learn to recognize whether the burning match is a chemical change or physical change.

What happened to the match?

When a change occurs to a substance, it can be either a Physical Change or a Chemical Change.

What do you think is the difference?

ChangesChanges

The melting point of gallium metal is 30˚C. The figure at left shows how the heat from a person’s hand can melt a sample of gallium.

Physical ChangesPhysical Changes

The shape of the sample changes during melting as the liquid begins to flow, but the composition of the sample does not change.

• Melting is a physical change.

• During a physical change, some properties of a material change, but the composition of the material does not change.

• Words such as boil, freeze, melt, and condense are used to describe physical changes.

• So are words such as break, split, grind, cut, and crush.

Chemical ChangesChemical Changes

Words such as burn, rot, rust, decompose, ferment, explode, and corrode usually signify a chemical change.

• The ability of a substance to undergo a specific chemical change is called a chemical property.

Chemical Changes

What always happens during a chemical change?

Iron is able to combine with oxygen to form rust.• The ability to rust is a chemical property

of iron.

Chemical properties can be used to identify a substance.• Chemical properties can be observed only

when a substance undergoes a chemical change.

During a chemical change, the composition of matter always changes.

Comparing ChangesComparing Changes

Examples of Changes

Physical Change Chemical Change

Matter that has a uniform and definite composition, with only one set of properties, is called a pure substance.

•Aluminum and copper are examples of pure substances.

Classifying a Substance… (grouping it)

Pure substances can either be an Element or a Compound.•Aluminum, Al, and Copper, Cu, are examples of elements.

•Water, H2O, and Salt, NaCl, are

examples of compounds.

Elements can be classified as Metals, Metalloids, or Nonmetals.•Copper is an example of a metal.

•Aluminum is an example of a metalloid

•Sulfur is an example of a nonmetal

Compounds can be classified as Organic or Inorganic.

•Sugar, C12H22O11, is an example of an

organic compound.

•Water, H2O, and Salt, NaCl, are

examples of inorganic compounds.

Inorganic compounds can be classified as Acid, Base, or Salt•H3PO4 is an example of an acid

compound.•NaOH is an example of a base compound. •CuSO4 is an example of salt

compound.

Classification of Matter

MATTERMATTER

PUREPURE

ELEMENTELEMENT

COMPOUNDCOMPOUND

NONMETALNONMETAL

METALLOIDMETALLOID

METALMETAL

ORGANIC

INORGANIC

SALTSALT

BASEBASE

ACIDACID

Matter that contains a physical blend of two or more components, each containing their original properties, is called a mixture

•Trail mix is an example of a mixture.

Describing Matter

Classifying MixturesClassifying Mixtures

How can mixtures be classified?

Heterogeneous Mixtures

In chicken noodle soup, the ingredients in the soup are not evenly distributed throughout the mixture.

• There is likely to be different amounts of chicken and noodles in each spoonful.

A mixture in which the composition is not uniform throughout is a heterogeneous mixture.

Heterogeneous Mixtures

Homogeneous Mixtures

The substances in the olive oil are evenly distributed throughout the mixture.• So, olive oil doesn’t

look like a mixture.

Homogeneous Mixtures

Olive oil and vinegar are both homogeneous mixtures.

• A homogeneous mixture is a mixture in which the composition is uniform throughout.

• Another name for a homogeneous mixture is a solution.

At the beach, you realize that both ocean water and sand are mixtures. Which is a homogeneous mixture (or solution)? Which is a heterogeneous mixture?

Salt water is a homogeneous mixture, or solution. Sand is a heterogeneous mixture.

Based on the distribution of their components, mixtures can be classified as heterogeneous mixtures or homogeneous mixtures.

Classification of Matter

MATTERMATTER

MIXTUREMIXTURE

PUREPURE

ELEMENTELEMENT

COMPOUNDCOMPOUND

HETEROGENEOUSHETEROGENEOUS

HOMOGENEOUSHOMOGENEOUS

NONMETALNONMETAL

METALLOIDMETALLOID

METALMETAL

ORGANIC

INORGANIC

SALTSALT

BASEBASE

ACIDACID

Separating MixturesSeparating Mixtures

Separating Mixtures

How can mixtures be separated?

Differences in physical properties can be used to separate mixtures.

Filtration

The coffee filter at right can separate ground coffee beans from brewed coffee.

• The liquid brewed coffee passes through the paper filter, but the solid coffee grounds cannot pass through the filter.

Filtration

Filter paper used in a laboratory is similar to coffee filters.

• Filter paper is often placed in a funnel.

• Then the mixture is poured into the funnel.

• Solid particles that cannot pass through the filter remain in the funnel.

• The rest of the particles pass through.

Distillation

Tap water is a homogeneous mixture of water and substances that are dissolved in the water.• One way to separate water from the other

components in tap water is through a process called distillation.

Distillation

During a distillation, a liquid is boiled to produce a vapor that is then condensed into a liquid.

Distillation

The figure below shows an apparatus used to perform a small-scale distillation.

Sample Problem 2.1Sample Problem 2.1

Separating a Heterogeneous Mixture

How could a mixture of aluminum nails and iron nails be separated?

In order to identify how to separate aluminum and iron nails, the properties of both aluminum and iron must be known.

Analyze Identify the relevant concepts.1

Solve Apply concepts to this situation.2

List the properties of each substance in the mixture.

Aluminum• metal• gray color• doesn’t dissolve

in water• not attracted to

magnet

Iron• metal• gray color• doesn’t dissolve

in water• attracted to

magnet

Solve Apply concepts to this situation.2

Identify a property that can be used to separate different substances from each other.• The ability to be attracted by a magnet is

a property that iron and aluminum do not share.

• You could use a magnet to remove the iron nails from a mixture of iron and aluminum.

Physical properties, such as melting point and boiling point, are used to describe all matter.

BIG IDEABIG IDEA

Chemistry as the Central Science

2.1 Properties of Matter > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights...

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