Chapter 2 Matter and Change 2.1 Properties of Matter 2.2 Mixtures 2.3 Elements and Compounds 2.4 Chemical Reactions

Objectives: 2.1 Properties of Matter Identify properties of matter as extensive and intensive Define physical properties Differentiate between the 3 states of matter

KEY TERMS Mass Volume Extensive Property Intensive Property Substance Physical Property Solid Liquid Gas Vapor Physical Change

Definitions Mass (m) – the amount of matter an object contains (a numerical value of its inertia) Volume(V) – the amount of space an object occupies Extensive property - a property that depends on the amount of matter an object contains Intensive property – a property that depends on type of matter an object contains Substance – matter with uniform properties Physical property - a quality or condition of a substance that can be observed without changing the composition of the substance

Definitions cont. Physical change - a change that do not affect the composition of a substance Chemical property – a quality or condition of a substance that can be observed with changing the composition of the substance

Why are windows made of glass? CHEMISTRY & YOU Why are windows made of glass? In this lesson, you will learn how properties can be used to classify and identify matter. Glass is transparent and heat resistant. Plastics degrade with UV light

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

Some Criteria for the Classification of Matter Properties State (solid, liquid, gas) Composition

Intensive and Extensive Properties Sulfur

Recall that matter is anything that has mass and takes up space. Extensive Properties Recall that matter is anything that has mass and takes up space. The mass of an object is a measure of the amount of matter the object contains. The mass of a basketball is greater than the mass of a golf ball. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

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

Who has a greater volume?

Mass and volume are both examples of extensive properties. An extensive property is a property that depends on the amount of matter in a sample. Examples: mass and volume Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

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

Identifying a Substance Matter that has a uniform and definite composition is called a substance. Aluminum and copper are examples of substances, which are also referred to as pure substances. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Examples of Physical Properties A physical property is a quality or condition of a substance that can be observed or measured without changing the substance’s composition. Examples: Color, odor, hardness, density, melting point, boiling point, state, solubility.

Example: Physical Properties 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 Red-brown -7 59 3.12 Water H2O 100 1.00 Sodium Chloride NaCl Solid White 801 1413 2.17

What are the 3 states of matter? Solid Liquid Gas

States of Matter Property Solid Liquid Gas Yes No Definite mass Definite volume No Definite shape Compressible Molecule Drawing Examples rock, cookie, gold bar Water, oil Air, helium, nitrogen

States of Matter Solid fixed shape and volume, incompressible Liquid fixed volume, takes the shape of its container Gas takes the volume and shape of its container

Bromine Gas (Vapor) Liquid

The melting point of gallium metal is 30˚C 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. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Change of Phase Melting solid  liquid Condensation gas  liquid Freezing liquid  solid Deposition gas  solid Evaporation liquid  gas Sublimation solid  gas *Boiling: Evaporation occurring beneath the liquid’s surface.

Is changing phase a physical or chemical change?

Physical Changes During a physical change, some properties of a material change, but the composition of the material does not change. Melting is a physical 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. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Do Now Name the phase change you see in the images.

Name the phase change

Name the phase change

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

Chemical Properties Chemical property – a quality or condition of a substance that can be observed with changing the composition of the substance Examples: Flammability rusting reactivity corrosion

2.2 MIXTURES Objectives: Categorize samples of matter into substance or mixture Differentiate between homogeneous and heterogeneous Describe two ways that components of mixtures can be separated

KEY TERMS Mixture - physical blend of 2 or more substances Heterogeneous – mixture in which the composition is not uniform throughout Homogeneous – mixture with a uniform composition throughout Phase – a part of a mixture with uniform composition Solution – another name for homogeneous mixture Filtration - a process that separates a solid from a liquid Distillation - a process that separates a solid dissolved in a liquid/ separation of 2 miscible liquids with different boiling temperatures Miscible - 2 or more liquids that can form a homogeneous mixture

Matter that has a uniform and definite composition. (Pure) Substance Matter that has a uniform and definite composition. Elements Compounds

Classification of Matter (by composition)

A physical blend of two or more substances. Mixture A physical blend of two or more substances.

Most samples of matter are mixtures. Describing Matter Most samples of matter are mixtures. Some mixtures are easier to recognize than others. You can easily recognize chicken noodle soup as a mixture of chicken, noodles, and broth. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Copper II Sulfate and its solution in water.

Mixtures can be classified as Homogenous mixtures Heterogeneous mixtures

A homogeneous mixture is a mixture in which the composition is the same throughout. Examples: olive oil, lemonade, coffee, air, alloys

Describing Matter Homogeneous Mixtures The substances in the olive oil are evenly distributed throughout the mixture. So, olive oil doesn’t look like a mixture. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Example: Stainless Steel A homogeneous mixture of: -Iron (Fe) -Chromium (Cr) -Nickel (Ni)

Note: Mixtures can be physically separated heterogeneous mixture: a mixture that is not uniform in composition; components are not evenly distributed throughout the mixture Examples: Oil and vinegar (mixed together) Salad Chicken soup Note: Mixtures can be physically separated

Separation Methods Use differences in the physical properties of the components of the mixture.

Example: Separate iron filings from sulfur using a magnet.

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

Distillation: -separate dissolved solids from a liquid -uses boiling and condensation.

Distillation of Crude Oil (Refining) Crude Oil is a mixture of Hydrocarbons

Distillation of Crude Oil

2.3 Elements and Compounds

Elements The simplest substances. Can not be separated into simpler substances. Building blocks of all matter. More than 100 known elements. Represented by chemical symbols.

Chemical Symbols of Elements System started by Jons Berzelius (Sweden, 1779-1848) 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

Compound (Ex: H2O -> liquid O2 -> gas H2 -> gas) A substance that contains two or more elements chemically combined. Can be broken down into simpler substances Compounds have different properties from the individual substances. (Ex: H2O -> liquid O2 -> gas H2 -> gas)

Properties of Compounds Distinguishing Elements and Compounds Properties of Compounds When the elements sodium and chlorine combine chemically to form sodium chloride, there is a change in composition and a change in properties. Sodium chloride (commonly known as table salt) is a white solid.

Breaking down Compounds Distinguishing Elements and Compounds Breaking down Compounds Breaking down NaCl Sodium is a soft gray metal.

Breaking down Compounds Distinguishing Elements and Compounds Breaking down Compounds Breaking down NaCl Chlorine is a pale yellow poisonous gas.

If composition is fixed and may not change substance Substance or mixture? If composition is fixed and may not change substance

2.4 Chemical Properties and Chemical Changes

H2O composition is fixed- compound Gaseous Phase Liquid Phase

Chemical Properties Chemical property - a quality or condition of a substance that can be observed with changing the composition of the substance Example: Magnesium reacts with oxygen to form magnesium oxide.

Magnesium Mg

Burning of Magnesium 2Mg+ O2 2MgO

Physical Change vs Chemical Change Physical change - Composition does not change. May be reversible or irreversible. Example of reversible: Liquid water -> steam Steam -> liquid water

Chemical Changes When charcoal is broken into smaller pieces, the change is a physical change. During a physical change, the composition of the matter never changes. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Chemical Change Chemical change - a change that produces matter with a different composition than the original matter. Atoms rearrange themselves into new combinations.

Chemical Changes Words that describe chemical changes: - Burn - decompose - rot - ferment - rust - corrode - explode Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

When the charcoal is heated and burned, a chemical change occurs. Chemical Changes When the charcoal is heated and burned, a chemical change occurs. The substances in charcoal react with oxygen in the air to form other substances. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Burning of Methane CH4 +2O2 CO2 + 2H2O

Burning of Methane CH4 + 2O2 CO2 + 2H2O

Recognizing a Chemical Change energy exchange production of a gas color change formation of a precipitate

Formation of a Precipitate Cu(OH)2 Precipitate

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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Example: H2O