Fundamentals of General, Organic, and BiochemistryFifth Editionby

McMurry, Castellion, and Ballantine

Chemistry:

The study of matter and the changes it undergoes. Define matter

What is meant here by change?

Three States of Matter

Solid: rigid - fixed volume and shapeSolid: rigid - fixed volume and shape

Liquid: definite volume but assumes the Liquid: definite volume but assumes the shape of its containershape of its container

Gas: no fixed volume or shape - Gas: no fixed volume or shape - assumes assumes the shape of its containerthe shape of its container

Link to Video

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AA homogeneous mixturehomogeneous mixture called a called a solution looks like pure substances solution looks like pure substances which are also homogeneouswhich are also homogeneous

AA heterogeneous mixtureheterogeneous mixture is, to the is, to the naked eye, clearly not uniformnaked eye, clearly not uniform

Pure Substances

Can be isolated from mixtures by Can be isolated from mixtures by separation methods:separation methods:

Chromatography FiltrationFiltration DistillationDistillation RecrystalizationRecrystalization

Pure Substances

Pure substances have specific Pure substances have specific unchanging physical and unchanging physical and chemical properties.chemical properties.Percent by mass of each Percent by mass of each

elementelementMelting points, Boiling pointsMelting points, Boiling pointsDensity at specified temperatureDensity at specified temperatureMany other propertiesMany other properties

Element:Element: A substance that cannot A substance that cannot be decomposed into simpler be decomposed into simpler substances by chemical means. substances by chemical means.

Compound:Compound: A substance with a A substance with a constant composition that can be constant composition that can be broken down into elements by chemical broken down into elements by chemical processes.processes.

Classification of Matter

Changes in Matter

Physical Changes are changes to matter that do not result in a change in the fundamental components that make that substance State Changes – boiling, melting,

condensing If you are talking about a specific substance

we call it a Physical Property of that substance.

Changes in Matter

Chemical Changes involve a change in the fundamental components of the substanceProduce a new substanceSpecific substance = Chemical Property

Classify Each of the following as Physical or Chemical Changes

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

but the material is still iron. Iron combines with oxygen to form

rust.. Chemical Property of Iron – describes how iron

and oxygen react to make a new substance, rust

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

becomes a new substance

Chemistry:

What do you know?

What do you think?

What do you believe?

Semester Key Idea

Knowing vs. Thinking

Observation

Qualitative and Quantitative

Hypothesis

Explains an observation. May be changed as soon as new information comes available.

Must be testable.

Experimentation

Checking your hypothesis by testing the “what if”

Steps in the Scientific Method

1.1. ObservationsObservationsquantitativequantitativequalitativequalitative

2.2. Formulating hypothesesFormulating hypothesespossible explanation for the possible explanation for the

observationobservation3.3. Performing experimentsPerforming experiments

gathering new information to gathering new information to decide decide whether the hypothesis is whether the hypothesis is validvalid

Outcomes Over the Long-Term

Theory (Model)Theory (Model)

A set of tested hypotheses that give anA set of tested hypotheses that give an overall explanation of some natural overall explanation of some natural

phenomenon.phenomenon.

Natural LawNatural Law

The same observation applies to manyThe same observation applies to many different systemsdifferent systems

Example - Law of Conservation of Example - Law of Conservation of MassMass

Law vs. Theory

A A lawlaw summarizes what happens. summarizes what happens.

A A theorytheory is an attempt to explain is an attempt to explain whywhy something happens. something happens.

The various parts of the scientific method. Note that The Law comes from the observations of the many experiments and does not attempt to explain the observations. The theory explains the observations.