chapter 3 matter. chapter 3 table of contents return to toc 3.1 matter 3.2 physical and chemical...

Chapter 3

Matter

Chapter 3

Table of Contents

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3.1 Matter

3.2 Physical and Chemical Properties and Changes

3.3 Elements and Compounds

3.4 Mixtures and Pure Substances

3.5 Separation of Mixtures

Section 3.1

Matter

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• Anything occupying space and having mass.• Matter exists in three states.

Solid Liquid Gas

Matter

Section 3.1

Matter

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The Three States of Water

Section 3.1

Matter

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• Rigid• Has a fixed volume and shape.• Examples:

Ice cube, diamond, iron bar

Solid

Section 3.1

Matter

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• Has a definite volume but no specific shape.• Assumes shape of container.• Examples:

Gasoline, water, alcohol, blood

Liquid

Section 3.1

Matter

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Liquid Water Takes the Shape of Its Container

Section 3.1

Matter

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• Has no fixed volume or shape.• Takes the shape and volume of its container.• Examples:

Air, helium, natural gas, oxygen

Gas

Section 3.2

Physical and Chemical Properties and Changes

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• The characteristics of matter that can be changed without changing its composition or doesn’t involve changing its composition. It’s an adjective.

• Characteristics that are directly observable.• Examples:

Odor, color, volume, state (s, l, or g), density, melting point, and boiling point

Physical Properties

Section 3.2


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• A substance’s ability to form new substances.• The characteristics that determine how the

composition of matter changes as a result of contact with other matter or the influence of energy. It’s an adjective.

• Characteristics that describe the behavior of matter.

• Examples: Flammability, steel

will rust, and Food will digest

Chemical Properties

Section 3.2


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Concept Check

Classify each of the following as a physical or chemical property. Ethyl alcohol will boil at 78°C Hardness of a diamond Sugar will ferment to form ethyl alcohol

physical

physical

chemical

Section 3.2


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• Change in the form of a substance, not in its chemical composition. It’s a verb.

• Example: Boiling or freezing water

Physical Change

Section 3.2


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• A given substance becomes a new substance or substances with different properties and different composition. It’s a verb.

• Example: Bunsen burner (methane

reacts with oxygen to form carbon dioxide and water)

Chemical Change

Section 3.2


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Electrolysis of Water Burning of Wood

Section 3.2


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• Water decomposes to hydrogen and oxygen gases.

Electrolysis of Water

Section 3.2


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Copyright © Cengage Learning. All rights reserved

Concept Check

How many of the following are examples of a chemical change?

Pulverizing (crushing) rock salt Burning of wood Dissolving of sugar in water Melting a popsicle on a warm summer day

Section 3.2


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Matter

Pure Substances

Mixtures

Compounds

(molecules)

Homogeneous

(solutions)

Heterogeneous(most things)

Elements

(atoms)

HydrogenOxygenCopperZinc

GraniteSandWoodOrange Juice

AirSodasOcean WaterAlcoholic drinks

WaterAlcoholSugarSalt

Separate by Physical Processes-filtering-distillation-centrifuging

Separate by Chemical Processes-burning-fermentation-rusting

1

Section 3.2


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Concept Check

Classify each of the following as a physical or chemical change.

Sugar fermenting to form ethyl alcohol Iron metal melting Iron combining with oxygen to form rust

chemical

physical

chemical

Section 3.3

Elements and Compounds

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• A substance that cannot be broken down into other substances by chemical methods.

• Examples: Iron (Fe), aluminum (Al), oxygen (O2), and

hydrogen (H2)

• All of the matter in the world around us contains elements.

Element

Section 3.4

Mixtures and Pure Substances

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• Always have the same composition and

are formed by chemical processes.• Either elements or compounds.• Examples:

Pure water (H2O), carbon dioxide (CO2), hydrogen (H2), gold (Au)

Pure Substances

Section 3.3


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• A substance composed of a given combination of elements that can be broken down into those elements by chemical methods.

• Examples: Water (H2O), carbon dioxide (CO2), table

sugar (C12H22O11)

• A compound always contains atoms of different elements.

• A compound always has the same composition (same combination of atoms).

Compound

Section 3.3


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Concept Check

How many of the following are compounds?

H2O, N2, NaOH, MnO2, H2

Three – H2O, NaOH, MnO2

Section 3.4


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• Have variable composition.• Examples

Wood, wine, coffee, granite• Can be separated into pure substances:

elements and/or compounds using physical processes.

Mixtures

Section 3.4


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• Same throughout.• Having visibly indistinguishable parts.• A solution.• Does not vary in composition from one region

to another.

Homogeneous Mixture

Apple Juice Cranberry Juice Orange Juice

Section 3.4


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• Air around you• Brass• Table salt stirred into water

Homogeneous Mixture – Examples

Section 3.4


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• Having visibly distinguishable parts.• Contains regions that have different properties

from those of other regions.

Heterogeneous Mixture

Section 3.4


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• Oil and vinegar dressing• Sand stirred into water

Heterogeneous Mixture – Examples

Section 3.4


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Concept Check

Which of the following is a homogeneous mixture?

Pure water Gasoline Jar of jelly beans Soil Copper metal

Section 3.5

Separation of Mixtures

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• Mixtures can be separated based on different physical properties of the components.

EvaporationVolatility

ChromatographyAdherence to a surface

FiltrationState of matter

(solid/liquid/gas)

DistillationBoiling point

TechniqueDifferent Physical Property

Section 3.5


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Distillation of a Solution Consisting of Salt Dissolved in Water

Section 3.5


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• No chemical change occurs when salt water is distilled.

Section 3.5


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The Organization of Matter

Section 3.5


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Filtration

• Separates a liquid from a solid.

Reverse Osmosis

• Separates a liquid from a solution. See Chapter 15.

Section 3.5


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Supercritical Carbon Dioxide Extraction

Maxwell House decaffeinates its coffee using pure water and natural effervescence. (1978) See Chapter 15.

A method of making reduced oil content in food chip products, such as potato chips and corn chips, includes circulating liquid carbon dioxide, over the food chip products to extract oil. Reduction of oil content to less than 50% of its initial value, including reductions to 25%, may be achieved while retaining flavor and texture comparable to conventional deep fried chips having an oil content of 30% to 40%. The oil which is recovered from the liquid carbon dioxide used for extraction has an appearance and quality which are substantially the same as virgin frying oil and may be reused to deep fry chips. SCF unit

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