Matter and ChangeMatter and Change

Chapter 1Chapter 1

1-1 Chemistry is a Physical 1-1 Chemistry is a Physical ScienceScience

• Chemistry is a Central Science – it Chemistry is a Central Science – it overlaps all other sciences.overlaps all other sciences.o It is the study of the composition, It is the study of the composition,

structure, and properties of matter structure, and properties of matter and the changes it undergoes.and the changes it undergoes.

o It is considered a physical science.It is considered a physical science.

• Instruments are often used to Instruments are often used to extend one’s ability to observe and extend one’s ability to observe and make measurements on matter.make measurements on matter.

• ALL matter- living, non-living or ALL matter- living, non-living or artificial- has a chemical basis.artificial- has a chemical basis.

Branches of ChemistryBranches of Chemistry

1.1. Organic Chemistry – Organic Chemistry –

2.2. Inorganic Chemistry-Inorganic Chemistry-

3.3. Physical Chemistry-Physical Chemistry-

4.4. Analytical Chemistry-Analytical Chemistry-

5.5. Biochemistry-Biochemistry-

6.6. Theoretical Chemistry-Theoretical Chemistry-

What is a Chemical?What is a Chemical?

• Chemical – any substance that has Chemical – any substance that has a definite composition. a definite composition. – Glucose, water, carbon dioxide, nylon Glucose, water, carbon dioxide, nylon

……

• Knowing the properties of Knowing the properties of chemicals allows scientists to chemicals allows scientists to understand uses.understand uses.

Basic ResearchBasic Research

• Is carried out for the sake of Is carried out for the sake of increasing knowledge, driven by increasing knowledge, driven by the desire to know.the desire to know.– Can explain the how’s and why’s of a Can explain the how’s and why’s of a

Rxn, properties of substances, …Rxn, properties of substances, …

• Example: DOW Chemical examines Example: DOW Chemical examines all Rxns involving chlorine.all Rxns involving chlorine.

Applied ResearchApplied Research

• This research is carried out to solve This research is carried out to solve a specific problem.a specific problem.

• Example: DOW chemical examines Example: DOW chemical examines how chlorine can be used as a how chlorine can be used as a disinfectant in drinking water.disinfectant in drinking water.

Technological Technological DevelopmentDevelopment

• Involves the production and use of Involves the production and use of products that improve the quality of life.products that improve the quality of life.– Technological development of a chemical Technological development of a chemical

product often lags behind basic research on product often lags behind basic research on the same substance.the same substance.

• Example: DOW chemical developed a Example: DOW chemical developed a more efficient method of disinfecting more efficient method of disinfecting water.water.

1-2 Matter and Its Properties1-2 Matter and Its Properties

• Matter – anything that has mass Matter – anything that has mass and volume.and volume.

2 General Properties of all 2 General Properties of all matter:matter:

• Volume – how much space an Volume – how much space an object takes up.object takes up.

• Mass – is a measure of the amount Mass – is a measure of the amount of matter in an object.of matter in an object.

Basic Building Blocks of MatterBasic Building Blocks of Matter

• Atom – the smallest unit of an Atom – the smallest unit of an element that maintains the element that maintains the properties of that element.properties of that element.

• Element – a pure substance made Element – a pure substance made of only one kind of atom.of only one kind of atom.

Basic Building Blocks of MatterBasic Building Blocks of Matter

• Compound – a substance that is made Compound – a substance that is made from the atoms of two or more elements from the atoms of two or more elements that are chemically bonded.that are chemically bonded.– A molecule can also be considered a compound A molecule can also be considered a compound

which binds together only nonmetals.which binds together only nonmetals.

– Water (HWater (H22O) – is a molecule which contains the O) – is a molecule which contains the elements hydrogen and oxygen. 1 atom oxygen, elements hydrogen and oxygen. 1 atom oxygen, 2 atoms hydrogen.2 atoms hydrogen.

Properties and Changes in Properties and Changes in MatterMatter

• Properties of matter can be used to Properties of matter can be used to distinguish between substances, distinguish between substances, separate them, and to classify separate them, and to classify substances.substances.

Properties and Changes in Properties and Changes in MatterMatter

• Extensive Properties – depend on Extensive Properties – depend on the amount of matter that is the amount of matter that is present.present.– Examples: Volume, Mass, …Examples: Volume, Mass, …

• Intensive Properties – do NOT Intensive Properties – do NOT depend on the amount of matter depend on the amount of matter present.present.– Examples: MP, BP, density, …Examples: MP, BP, density, …

Physical Properties and Physical Physical Properties and Physical ChangesChanges

• Physical Property – characteristic of Physical Property – characteristic of a substance that can be observed a substance that can be observed without altering the identity of a without altering the identity of a substance.substance.– MP of water MP of water 0 0C C – BP of water BP of water 100 100CC

Physical Properties and Physical Physical Properties and Physical ChangesChanges

• Physical Change – process by which Physical Change – process by which a substance undergoes a change a substance undergoes a change that does not alter its identity.that does not alter its identity.– Example: cutting, grinding, melting, Example: cutting, grinding, melting,

boiling, tearing, painting, …boiling, tearing, painting, …

Physical Properties and Physical Physical Properties and Physical ChangesChanges

• Change of State – physical change of a Change of State – physical change of a substance from one phase(state) of substance from one phase(state) of matter to anothermatter to another– Melting Melting solid to liquid solid to liquid– Boiling Boiling liquid to gas liquid to gas

• A change of state does not alter the A change of state does not alter the identity of a substanceidentity of a substance– If water boils, it is still waterIf water boils, it is still water

4 States of Matter4 States of Matter

• Solid – definite volume and shapeSolid – definite volume and shape• Liquid – definite volume, no definite Liquid – definite volume, no definite

shapeshape• Gas – no definite volume, no Gas – no definite volume, no

definite shapedefinite shape• Plasma - no definite volume, no Plasma - no definite volume, no

definite shapedefinite shape

Chemical PropertiesChemical Properties

• Chemical Property – characteristic of a Chemical Property – characteristic of a substance that cannot be observed substance that cannot be observed without altering the identity of the without altering the identity of the substance.substance.– Transfers one substance into another.Transfers one substance into another.– Observed when a chemical changes into a Observed when a chemical changes into a

new substancenew substance

• Example: gasoline burns in oxygen to Example: gasoline burns in oxygen to form water and carbon dioxideform water and carbon dioxide

Chemical ChangesChemical Changes

• Chemical Change (Chemical Rxn) – a Chemical Change (Chemical Rxn) – a change in which one or more substances change in which one or more substances are converted into different substances.are converted into different substances.

• Example: Decomposition of hydrogen Example: Decomposition of hydrogen peroxideperoxide– Reactant Reactant Product Product – Hydrogen peroxide Hydrogen peroxide water + oxygen gas water + oxygen gas

Chemical ChangesChemical Changes

• Example: Burning CharcoalExample: Burning Charcoal– Carbon + oxygen Carbon + oxygen carbon dioxide carbon dioxide

• During any chemical Rxn, the During any chemical Rxn, the amount of matter (and mass) amount of matter (and mass) remains the sameremains the same

Energy and Changes in MatterEnergy and Changes in Matter

• When physical and chemical changes When physical and chemical changes occur, energy usually is transferred.occur, energy usually is transferred.

• Energy can be absorbed or released, but Energy can be absorbed or released, but energy cannot be created nor energy cannot be created nor destroyeddestroyed. . Law of Conservation of Law of Conservation of EnergyEnergy

Classification of MatterClassification of Matter

• See fig. 1-8, pg. 15See fig. 1-8, pg. 15• Mixture – is a blend of two or more Mixture – is a blend of two or more

kinds of matter, each which retains kinds of matter, each which retains its own identity and properties.its own identity and properties.

• Parts are just mixed together.Parts are just mixed together.

Two Types of MixturesTwo Types of Mixtures

o Homogenous mixture – mixture Homogenous mixture – mixture uniform in composition.uniform in composition.o Example: sugar water, Air, Flat Pop, Example: sugar water, Air, Flat Pop,

……

Two Types of MixturesTwo Types of Mixtures

o Heterogeneous mixture – mixture which are Heterogeneous mixture – mixture which are NOT uniform throughout.NOT uniform throughout.o Often has its own visible parts.Often has its own visible parts.o Example: Iron ore, rock, cookie, milk,…Example: Iron ore, rock, cookie, milk,…

• Discuss Filtering Techniques: Fig. 1-9, pg. 16Discuss Filtering Techniques: Fig. 1-9, pg. 16

Pure SubstancePure Substance

• Has a fixed composition.Has a fixed composition.• Has exactly the same characteristic Has exactly the same characteristic

properties.properties.• Has exactly the same composition.Has exactly the same composition.• Can be either compounds or elements.Can be either compounds or elements.

– Example: Water, pure metals, oxygen gas, Example: Water, pure metals, oxygen gas, ……

1-3 Elements1-3 Elements

• Elements are pure substances Elements are pure substances which cannot be broken down by which cannot be broken down by chemical means.chemical means.

• Use blank periodic table we created Use blank periodic table we created in class to understand key terms.in class to understand key terms.