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Chapter 1Chapter 1

Introduction to ChemistryIntroduction to Chemistry

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What is Chemistry?What is Chemistry? The study of the matter, its composition, The study of the matter, its composition,

properties, and the changes it properties, and the changes it undergoes.undergoes.

Applied chemistryApplied chemistry is the using chemistry is the using chemistry to attain certain goals, in fields like to attain certain goals, in fields like medicine, agriculture, and medicine, agriculture, and manufacturingmanufacturing

Pure chemistryPure chemistry gathers knowledge for gathers knowledge for knowledge’s sakeknowledge’s sake

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Which Comes First?Which Comes First? Pure ChemistryPure Chemistry

Usually comes first, Usually comes first, applied laterapplied later

Called Called technologytechnology

Or engineeringOr engineering

Pure chemistry can Pure chemistry can explain behavior that explain behavior that has been used has been used without knowing whywithout knowing why

Steel swordsSteel swords

Applied ChemistryApplied Chemistry

Can’t be good or Can’t be good or badbad

Can be good or bad Can be good or bad depending on usedepending on use

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Branches of ChemistryBranches of Chemistry Analytical ChemistryAnalytical Chemistry -studies composition of -studies composition of

substances.substances. Organic ChemistryOrganic Chemistry -compounds containing -compounds containing

carboncarbon Inorganic ChemistryInorganic Chemistry -substances without -substances without

carboncarbon BiochemistryBiochemistry- Chemistry of living things- Chemistry of living things Physical ChemistryPhysical Chemistry studies behavior of studies behavior of

substancessubstances– rates and mechanisms of reactionsrates and mechanisms of reactions– energy transfersenergy transfers

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Why study ChemistryWhy study Chemistry Explain the natural worldExplain the natural world

– Why?Why? Prepare for a careerPrepare for a career

– Directly- in a labDirectly- in a lab– Indirectly- problem solving and thinking Indirectly- problem solving and thinking

skillsskills Be an informed citizenBe an informed citizen

– VoteVote– Don’t get scammedDon’t get scammed

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Applied ChemistryApplied Chemistry Material DesignMaterial Design

– PlasticsPlastics– PaintsPaints– NanotechnologyNanotechnology

ScaleScale– Macroscopic-Macroscopic- Big enough to see Big enough to see– Microscopic-Microscopic- Too small to see unaided Too small to see unaided– Nanotechnology-Nanotechnology- manipulating manipulating

individual atoms and molecules individual atoms and molecules

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Applied ChemistryApplied Chemistry EnergyEnergy

– Ability to do workAbility to do work Different types can be converted to each Different types can be converted to each

otherother ConservationConservation

– More efficient conversionMore efficient conversion– InsulationInsulation

Production –new sourcesProduction –new sources Storage- batteries, fuel cellsStorage- batteries, fuel cells

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Applied ChemistryApplied Chemistry AgricultureAgriculture

– Production- fertilizers, soil testsProduction- fertilizers, soil tests– Protection – pesticide, herbicideProtection – pesticide, herbicide

MedicineMedicine– DrugsDrugs– Materials- hips, artificial skinMaterials- hips, artificial skin– Biotechnology- using organisms as a Biotechnology- using organisms as a

means of production means of production

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Applied ChemistryApplied Chemistry Environment- PollutionEnvironment- Pollution

– Eliminate sourcesEliminate sources– Treatment once pollutedTreatment once polluted

AstronomyAstronomy– Remote analysis of stars from their Remote analysis of stars from their

lightlight– Analysis of extraterrestrial samplesAnalysis of extraterrestrial samples

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AlchemyAlchemy Forerunner of chemistryForerunner of chemistry Mystical- search for perfectionMystical- search for perfection Practical- developed glassware and Practical- developed glassware and

techniques used todaytechniques used today Tried to change elementsTried to change elements Faulty assumptions and lack of logic led Faulty assumptions and lack of logic led

them astraythem astray

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Scientific MethodScientific Method A way of solving problems or answering A way of solving problems or answering

questions.questions. Starts with Starts with observationobservation- noting an - noting an

recording factsrecording facts Hypothesis-Hypothesis- a possible explanation as a possible explanation as

to the cause of the observation, based to the cause of the observation, based on research and previous knowledgeon research and previous knowledge

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Scientific MethodScientific Method ExperimentExperiment- designed to test the - designed to test the

hypothesishypothesis only two possible answersonly two possible answers

– hypothesis is righthypothesis is right– hypothesis is wronghypothesis is wrong

Generates Generates datadata -observations from -observations from experiments.experiments.

Modify hypothesis - repeat the cycleModify hypothesis - repeat the cycle

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VariablesVariables Controlled experiment-Controlled experiment- Only want one Only want one

thing to change at a time in a laboratory.thing to change at a time in a laboratory. Manipulated variable-Manipulated variable- What you change What you change

or control directly or control directly Also called Also called independentindependent variable variable Responding variableResponding variable – What changes – What changes

as a result. No direct controlas a result. No direct control Also called Also called dependentdependent variable variable

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Observations

Hypothesis

Experiment

Cycle repeats many Cycle repeats many times.times.

By you and by othersBy you and by others The hypothesis gets The hypothesis gets

more and more certain.more and more certain. Becomes a Becomes a theorytheory A thoroughly tested A thoroughly tested

model that explains why model that explains why things behave a certain things behave a certain way.way.

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Theory can never Theory can never be proven.be proven.

It is the best It is the best explanationexplanation

Useful because Useful because they predict they predict behaviorbehavior

Help us form mental Help us form mental pictures of pictures of processes (processes (modelsmodels))

Observations

Hypothesis

Experiment

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Another outcome is Another outcome is that certain behavior that certain behavior is repeated many is repeated many timestimes

Scientific Scientific LawLaw is is developeddeveloped

Description of how Description of how things behave things behave

Usually an equationUsually an equation Law - howLaw - how Theory- whyTheory- why

Observations

Hypothesis

Experiment

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Prediction

Experiment

Modify

Observations

Hypothesis

Experiment

Law

Theory(Model)

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CommunicationCommunication Use JournalsUse Journals

– Do researchDo research– Write articleWrite article

»Describe procedures,Describe procedures, methods, and findings methods, and findings

– Submit for peer reviewSubmit for peer review»Sent back for editingSent back for editing

– PublishPublish»Letters to editor Letters to editor

respond.respond.

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CollaborationCollaboration Working togetherWorking together TeamsTeams

– Different skills Different skills – Different specialtiesDifferent specialties

Internet and EmailInternet and Email ConferencesConferences

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Problem SolvingProblem Solving Only way to get good is to practiceOnly way to get good is to practice Two partsTwo parts

– Developing Plan-Developing Plan-»Hard partHard part»Higher level thinkingHigher level thinking

– Implementing Plan-Implementing Plan-»Not so hardNot so hard»Application levelApplication level

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Solving Numeric ProblemsSolving Numeric Problems Three steps-Three steps-

1.1. AnalyzeAnalyze» KnownKnown

NumbersNumbers MeasurementsMeasurements EquationsEquations

» UnknownUnknown What are you looking for?What are you looking for? What units?What units?

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Solving Numeric ProblemsSolving Numeric Problems Three steps-Three steps-

1.1. AnalyzeAnalyze» PlanPlan

The heart of problem solvingThe heart of problem solving DiagramDiagram Look infoLook info

– TableTable– GraphGraph– EquationEquation

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Solving Numeric ProblemsSolving Numeric Problems Three steps-Three steps-

1.1. AnalyzeAnalyze2.2. CalculateCalculate

» Easiest partEasiest part» Convert measurementsConvert measurements» RearrangeRearrange» Appendix CAppendix C

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Solving Numeric ProblemsSolving Numeric Problems Three steps-Three steps-

1.1. AnalyzeAnalyze2.2. CalculateCalculate3.3. EvaluateEvaluate

» Reasonable?Reasonable?» Read the question, did you Read the question, did you

answer it?answer it?» Check your workCheck your work» EstimateEstimate

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PracticePractice What is the length, in centimeters, of a What is the length, in centimeters, of a

10.0-inch ruler, given that there are 2.54 10.0-inch ruler, given that there are 2.54 centimeters per inch?centimeters per inch?

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PracticePractice A certain ball when dropped from any A certain ball when dropped from any

height, bounces one-half the original height, bounces one-half the original height. If the ball was dropped from a height. If the ball was dropped from a height of 60 in. and allowed to bounce height of 60 in. and allowed to bounce freely, what is the total distance the ball freely, what is the total distance the ball has traveled when it hits the ground for has traveled when it hits the ground for the third time? Assume the ball bounces the third time? Assume the ball bounces straight up and down.straight up and down.

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Conceptual ProblemsConceptual Problems Without numbers or mathWithout numbers or math Two stepsTwo steps

1.1. AnalyzeAnalyze» Identify known and unknownIdentify known and unknown» PlanPlan

2.2. SolveSolve

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PracticePractice You find a sealed box You find a sealed box

with strings protruding with strings protruding from three holes, as from three holes, as shown in the diagram. shown in the diagram. When you tug string A, it becomes When you tug string A, it becomes longer and string C becomes shorter. longer and string C becomes shorter. When you tug string B, it becomes When you tug string B, it becomes longer, but strings A and C are not longer, but strings A and C are not affected. Make a diagram showing the affected. Make a diagram showing the arrangement of the strings inside the arrangement of the strings inside the box.box.