matter chapter 3 1

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Matter

Chapter 3

Why does soda fizz when you open the bottle?

Why is the sun hot? When iron rusts, what’s happening?

Objectives

• Observe and explain the difference between states of matter.

Copyright©2004 by Houghton Mifflin Company. All rights

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3-1 Universe Classified

• Matter is the part of the universe that has mass and volume

- There are three states of matterSolid, liquid, and gas

• Chemistry is the study of matter– The properties of different types of matter– The way matter behaves when influenced by other

matter and/or energy

Some Criteria for the Classification of Matter

• Composition (elements and compounds)

• State (solid, liquid, gas)

• Properties

States of Matter

YES YES YES

YES YES

YES

NO

NO

NO

NO

NO

YES

States of Matter

Figure 3.1: Liquid water takes the shape of its container.

• Teacher Website Select Interactive 1



Figure 3.11: In ice, the water molecules vibrate randomly about their positions in the solid. Their motions are represented by arrows.


Figure 3.12: Equal masses of hot water and cold water separated by a thin metal wall in an insulated box.


Figure 3.13: The H2O molecules in hot water have much greater random motions than the H2O molecules in cold water.


Figure 3.14: The water samples now have the same temperature (50°C) and have the same random motions.

Phase ChangesMelting solid liquidCondensation gas liquid

Freezing liquid solid

Deposition gas solid

Evaporation liquid gasSublimation solid gas

*Boiling: Evaporation occurring beneath the liquid’s surface.

Gallium metal has such a low melting point (30°C) that it melts from the heat of a hand.

NAME THAT PHASE CHANGE

Video - https://www.youtube.com/watch?v=wln6WSv-cro

https://www.youtube.com/watch?v=wln6WSv-cro

https://www.youtube.com/watch?v=wln6WSv-cro

Objectives

• Explain the difference between elements and compounds.


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3-3 Elements and Compounds

• a pure substance

• same composition throughout

• Contains only one type of atom

• Can not be broken down into simpler substances by ordinary chemical reactions (not a nuclear reaction)

Element

Chemical Symbols of Elements

• System started by Jons Berzelius (Sweden, 1779-1848)

• 90-91 naturally occurring elements• One or two first letters of name of the

element.

• Many elements names have roots from: Latin, Greek, mythology, geography, names of scientists.

Examples:• Americium, Am

• Einsteinium, Es

• Bromine, Br

• Helium, He

• Lead(Plumbum), Pb

• Niobium, Nb

• Iron (Ferrum), Fe

• Mendelevium, Md

Examples of other elements: O2, H2, I2

Compound – chemical combination of two or more elements

Have two properties in common with elements:

1. pure substance2. Homogeneous – same chemical composition at all times

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Compound

Compounds cont.

Have two properties that differ from elements:

1.two or more elements that are chemically combined, in a definite ratio

2. Compounds can be broken down by chemical reactions using energy:

a) decomposition - uses heatb) electrolysis - uses electricity

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> 10 million compounds

•elements are represented by symbols•compounds are represented by chemical formulas

•chemical formula1. symbol --> tells which elements are present in compounds2. subscript (little # lower right) --> tells the number of atoms of each element

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When the elements sodium and chlorine combine chemically to form sodium chloride, there is a change in composition and a change in properties.

Properties of Compounds

• Sodium chloride (commonly known as table salt) is a white solid.

Distinguishing ElementsDistinguishing Elementsand Compoundsand Compounds

Compounds have different properties from their individual elements.

Breaking down Compounds

Breaking down NaCl

•Sodium is a soft gray metal.


Breaking down NaCl

Breaking down Compounds

• Chlorine is a pale yellow poisonous gas.


Classification of Matter(by composition)

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Classification of Matter

P u re S ub s ta n ceC o n s tan t C o m p o s it ion

H o m o ge n e o us

M ix tu reV a ria b le C o m p o s it ion

M a tte r

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3-4 Mixtures

Mixtures can be classified as:•Homogeneous Mixtures

•Heterogeneous Mixtures

• Homogeneous mixture = uniform throughout, appears to be one layer– Also called solutions

– Examples: olive oil, salt water, lemonade, coffee, air

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The substances in the olive oil are evenly distributed throughout the mixture

Example: Stainless SteelA homogeneous

mixture of: -Iron (Fe) -Chromium (Cr)-Nickel (Ni)

• Heterogeneous mixture = non-uniform, contains regions with different properties than other regions

- Examples: oil and vinegar, salad, chicken soup

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Pure Substances vs. Mixtures• Pure Substances

– All samples have the same physical and chemical properties– Constant Composition all samples have the same composition– Homogeneous– Separate into components based on chemical properties

• Mixtures– Different samples may show different properties– Variable composition– Homogeneous or Heterogeneous– Separate into components based on physical properties

• All mixtures are made of pure substances


Figure 3.4: When table salt is stirred into water (left), a homogeneous mixture called a solution forms (right).


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Identity Each of the following as a Pure Substance, Homogeneous Mixture or

Heterogeneous Mixture

Gasoline

A stream with gravel on the bottom

Copper metal


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Identity Each of the following as a Pure Substance, Homogeneous Mixture or

Heterogeneous MixtureGasoline

– a homogenous mixture

A stream with gravel on the bottom– a heterogeneous mixture

Copper metal– A pure substance (all elements are pure substances)


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3-5 Separation of Mixtures• Separate mixtures based on different

physical properties of the components

EvaporationVolatility

ChromatographyAdherence to a Surface

FiltrationState of Matter (solid/liquid/gas)

DistillationBoiling Point

TechniqueDifferent Physical Property

Example: Separate iron filings from sulfur using a magnet.

Filtration: separates a solid from a liquid in a heterogeneous mixture


Figure 3.6: Distillation of a solution consisting of salt dissolved in water.

-separate dissolved solids from a liquid in a homogeneous mixture

-uses boiling and condensation.

Distillation of Crude Oil (Refining)

• Crude Oil is a mixture of Hydrocarbons

Distillation of Crude Oil

Paper Chromatography

Chromatography separates mixtures of substances into their components.They all have:• a stationary phase (a solid, or a liquid supported on a solid) •and a mobile phase (a liquid or a gas).


Properties of Matter


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Extensive Propertiesmass –

Volume –

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

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a measure of the amount of matter the object contains.

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

Who has a greater volume?

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An extensive property is a property that depends on the amount of matter in a sample. Examples: mass and volume

Extensive Properties

Objectives

• Observe and explain the difference between states of matter.

• Explain the difference between physical and chemical changes.


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Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

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– An intensive property is a property that depends on the type of matter in a sample, not the amount of matter.

Examples include:

- Hardness of an object -Color- Softness -Boiling point- Absorbency -Odor

Intensive Properties

Is changing phase a physical or chemical change?

3-2 Physical and Chemical Properties and Changes


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Properties of Matter• Physical Properties are the characteristics

of matter that can be changed without changing its composition

– Characteristics that are directly observable

– Examples: Color, odor, hardness, density, melting point, boiling point, state, solubility.

Substance State Color Melting Point (C°)

Boiling Point (C°)

Density (g/cm3)

Oxygen O2 Gas Colorless -218 -183 0.0014

Mercury Hg Liquid Silvery-white

-39 357 13.5

Bromine Br2 Liquid Red-brown -7 59 3.12

Water H2O Liquid Colorless 0 100 1.00

Sodium Chloride

NaCl Solid White 801 1413 2.17

Example: Physical Properties

Properties of Matter• Chemical Properties are the characteristics

that determine how the composition of matter changes as a result of contact with other matter

- Examples: burning, decompose, reactivity, corrode, tarnish, explode, ferment


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Classify Each of the following as Physical or Chemical Properties

The boiling point of ethyl alcohol is 78°C.

Diamond is very hard.

Sugar ferments to form ethyl alcohol.


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Classify Each of the following as Physical or Chemical Properties

The boiling point of ethyl alcohol is 78°C.– Physical property – describes inherent characteristic of

alcohol – boiling pointDiamond is very hard.

– Physical property – describes inherent characteristic of diamond – hardness

Sugar ferments to form ethyl alcohol.– Chemical property – describes behavior of sugar –

forming a new substance (ethyl alcohol)

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Changes in Matter• Physical Changes are changes to matter that do

not result in a change in the composition

– State Changes – boiling, melting, condensing– Breaking, splitting, grinding, cutting

• Chemical Changes involve a change in the composition of the substance– Produce a new substance– Chemical reaction– Reactants Products

Indications of a Chemical Reaction

• Color change• Solid forms (precipitate)• Gas bubbles• Odor• Temperature change• Fizzing


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Formation of a Precipitate

Cu(OH)2

Precipitate


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Classify Each of the following as Physical or Chemical Changes

Iron metal is melted.

Iron combines with oxygen to form rust.

Sugar ferments to form ethyl alcohol.


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Classify Each of the following as Physical or Chemical Changes

Iron is melted.– Physical change – describes a state change, but the

material is still ironIron combines with oxygen to form rust..

– Chemical change – describes how iron and oxygen react to make a new substance, rust

Sugar ferments to form ethyl alcohol.– Chemical change – describes how sugar forms a new

substance (ethyl alcohol)

Oxygen combines with the chemicals in wood to produce flames. Is a physical or chemical change taking place?

Source: Jim Pickerell/Stone/Getty Images

Burning of MethaneCH4 +2O2 CO2 + 2H2O

l_______________l l_________________l l l

reactants products

Burning of MethaneCH4 + 2O2 CO2 + 2H2O

In a chemical change, what happens to matter that appears

to be lost?

The Law of Conservation of Mass (Antoine Lavoisier)

• In any chemical or physical change, mass is neither created or destroyed

• Mass is CONSTANT

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