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Chapter 1Chapter 1““Introduction to Chemistry”Introduction to Chemistry”

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Section 1.1Section 1.1ChemistryChemistry

OBJECTIVES:OBJECTIVES:–Identify Identify five traditional areasfive traditional areas

of study in chemistry.of study in chemistry.–Relate Relate purepure chemistry to chemistry to

appliedapplied chemistry. chemistry.–Identify Identify reasonsreasons to study to study

chemistry.chemistry.

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What is Chemistry?What is Chemistry? Chemistry is the study of the composition of Chemistry is the study of the composition of

“matter” its composition, properties, and the “matter” its composition, properties, and the changes it undergoes.changes it undergoes.

Matter - Matter - anything with mass and occupies anything with mass and occupies spacespace

Chemistry has a definite affect on everyday Chemistry has a definite affect on everyday life - taste of foods, grades of gasoline, etc.life - taste of foods, grades of gasoline, etc.

Living and nonliving things are made of Living and nonliving things are made of matter.matter.

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Chemistry is the study of the composition, structure, and properties of matter and the changes it undergoes – such as burning fuels.

C2H5OH + 3 O2 2 CO2 + 3 H2O + Energy

Reactants Products

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5 Major Areas of Chemistry5 Major Areas of Chemistry1)1) Analytical ChemistryAnalytical Chemistry- - concerned with concerned with

the composition of substances.the composition of substances.2)2) Inorganic ChemistryInorganic Chemistry- - primarily deals primarily deals

with substances without carbonwith substances without carbon3)3) Organic ChemistryOrganic Chemistry- - essentially all essentially all

substances containing carbonsubstances containing carbon4)4) BiochemistryBiochemistry- - Chemistry of living thingsChemistry of living things5)5) Physical ChemistryPhysical Chemistry- - describes the describes the

behavior of chemicals (ex. stretching); behavior of chemicals (ex. stretching); involves lots of math!involves lots of math!

Boundaries not firm – they overlap and interactBoundaries not firm – they overlap and interact

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What is Chemistry?What is Chemistry? Pure chemistry-Pure chemistry- gathers knowledge for gathers knowledge for

the the sake of knowledgesake of knowledge Applied Chemistry-Applied Chemistry- is using chemistry is using chemistry

to to attain certain goalsattain certain goals, in fields like , in fields like medicine, agriculture, and medicine, agriculture, and manufacturingmanufacturing – leads to an application – leads to an application

* Nylon* Nylon

* Aspirin (C* Aspirin (C99HH88OO44))

* Use of TECHNOLOGY* Use of TECHNOLOGY

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Why Study Chemistry?Why Study Chemistry? Everyone and everything around us Everyone and everything around us

involves chemistry – explains our worldinvolves chemistry – explains our world What in the world isn’t Chemistry?What in the world isn’t Chemistry? Helps you make choices; helps make Helps you make choices; helps make

you a better informed citizenyou a better informed citizen A possible career for your futureA possible career for your future Used to attain a specific goalUsed to attain a specific goal

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Why Study Chemistry?Why Study Chemistry?With a partner…With a partner…

–Give examples in your daily Give examples in your daily life that life that involve use of involve use of chemistrychemistry, and things that , and things that do do not?not?

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Section 1.2Section 1.2Chemistry Far and WideChemistry Far and Wide

OBJECTIVES:OBJECTIVES:

–Identify some Identify some areas of areas of researchresearch affected by affected by chemistry.chemistry.

–Describe some Describe some examplesexamples of research in chemistry.of research in chemistry.

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Section 1.2Section 1.2Chemistry Far and WideChemistry Far and Wide

OBJECTIVES:OBJECTIVES:

–Distinguish between Distinguish between macroscopicmacroscopic and and microscopicmicroscopic views. views.

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Chemistry Far and WideChemistry Far and Wide Chemists design materials to fit Chemists design materials to fit

specific needsspecific needsEx.) velcro, perfume, steel, ceramics, Ex.) velcro, perfume, steel, ceramics, plastics, rubber, paints, nonstick plastics, rubber, paints, nonstick cooking utensils, polyester fiberscooking utensils, polyester fibers

Two different ways to look at the Two different ways to look at the world: world:

1.1. MacroscopicMacroscopic2.2. MicroscopicMicroscopic

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Chemistry Far and WideChemistry Far and Wide Energy – we constantly have Energy – we constantly have

greater demandsgreater demands Q: How can we meet these Q: How can we meet these

demands?demands? A: A: Conserve it or use it wiselyConserve it or use it wisely

Ex.) Ex.) fossil fuels, solar, wind, fossil fuels, solar, wind, batteries (that store energy – or batteries (that store energy – or rechargeable), nuclearrechargeable), nuclear

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Chemistry Far and WideChemistry Far and WideMedicine and Biotechnology-Medicine and Biotechnology-

–Supply materials doctors use to Supply materials doctors use to treat patientstreat patients

–vitamin C, penicillin, aspirin vitamin C, penicillin, aspirin (C(C99HH88OO44))

–materials for artery transplants materials for artery transplants and hipbonesand hipbones

–bacteria producing insulinbacteria producing insulin

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Chemistry Far and WideChemistry Far and WideNorman BorlaugNorman Borlaug

Nobel Peace PrizeNobel Peace Prize Presidential Medal Presidential Medal

of freedomof freedom Congressional Congressional

Gold MedalGold Medal Father of the Father of the

Green RevolutionGreen Revolution Credited with Credited with

saving over 1 saving over 1 billion people from billion people from starvationstarvation

Agriculture

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Chemistry Far and WideChemistry Far and Wide AgricultureAgriculture

–increase the world’s food supplyincrease the world’s food supply

–Use chemistry for better Use chemistry for better productivity – soil, water, weedsproductivity – soil, water, weeds

–plant growth hormonesplant growth hormones

–ways to protect crops; insecticidesways to protect crops; insecticides

–disease resistant plantsdisease resistant plants

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Chemistry Far and WideChemistry Far and Wide The EnvironmentThe Environment

–both risks and benefits involved in both risks and benefits involved in discoveriesdiscoveries

–Pollutants need to be Pollutants need to be

–1) 1) identifiedidentified and 2) and 2) preventedprevented

–Lead paint was prohibited in 1978; Lead paint was prohibited in 1978; Leaded gasoline? Drinking water?Leaded gasoline? Drinking water?

–carbon dioxide, ozonecarbon dioxide, ozone

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88.2%

440,000

After lead was banned in gasoline and public water supply systems, less lead entered the environment.

Let’s examine some information from a graph.

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Chemistry Far and WideChemistry Far and WideThe UniverseThe Universe

–Need to gather data from afar, Need to gather data from afar, and analyze matter brought back and analyze matter brought back to Earthto Earth

–composition of the planetscomposition of the planets–analyze moon rocksanalyze moon rocks–planet atmospheresplanet atmospheres–life on other planets?life on other planets?

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Section 1.3Section 1.3Thinking Like a ScientistThinking Like a Scientist

OBJECTIVES:OBJECTIVES:

–Describe how Lavoisier Describe how Lavoisier transformed chemistry.transformed chemistry.

–Identify three steps in the Identify three steps in the scientific method.scientific method.

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Section 1.3Section 1.3Thinking Like a ScientistThinking Like a Scientist

OBJECTIVES:OBJECTIVES:

–Explain why collaboration Explain why collaboration and communication are and communication are important in science.important in science.

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AlchemyAlchemy – – developed the developed the tools and tools and techniquestechniques for working with chemicals for working with chemicals

The word The word chemistrychemistry comes from comes from alchemyalchemy – practiced in China and – practiced in China and India since 400 India since 400 B.C.B.C.

Alchemy has two sides:Alchemy has two sides:

–Practical: Practical: techniquestechniques for working for working with metals, glass, dyes, etc.with metals, glass, dyes, etc.

–Mystical: Mystical: conceptsconcepts like perfection – like perfection – gold was a perfect metal gold was a perfect metal

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An Experimental ApproachAn Experimental Approach In the 1500s, a shift started from In the 1500s, a shift started from

alchemy to science – King Charles alchemy to science – King Charles II was a supporter of the sciencesII was a supporter of the sciences

““Royal Society of London for the Royal Society of London for the Promotion of Natural Knowledge”Promotion of Natural Knowledge”

Encouraged scientists to use more Encouraged scientists to use more experimental evidence, and not experimental evidence, and not philosophical debatesphilosophical debates

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LavoisierLavoisier In the late 1700s, In the late 1700s, Antoine Antoine

LavoisierLavoisier helped transform helped transform chemistry from a chemistry from a science of science of observationobservation to the to the science of science of measurementmeasurement – still used today – still used today

He settled a long-standing debate He settled a long-standing debate about burning, which was…about burning, which was…

–OxygenOxygen was required! was required!

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The Scientific MethodThe Scientific Method A logical approach to solving A logical approach to solving

problems or answering questions.problems or answering questions. Starts with Starts with observationobservation- - noting and noting and

recording information and factsrecording information and facts hypothesishypothesis- - a proposed a proposed

explanation for the observation; explanation for the observation; must be tested by an experimentmust be tested by an experiment

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Steps in the Scientific Steps in the Scientific MethodMethod

1. Observations (uses your senses)1. Observations (uses your senses)a)a) quantitative involves quantitative involves numbersnumbers = 95= 95ooFFb)b) qualitative is qualitative is word description = hotword description = hot

2. 2. Formulating hypotheses (ideas)Formulating hypotheses (ideas)- possible explanation for the - possible explanation for the observation, or “educated” guess observation, or “educated” guess

3. 3. Performing experiments (the test)Performing experiments (the test)- gathers new information to help decide- gathers new information to help decide

whether the hypothesis is validwhether the hypothesis is valid

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Scientific MethodScientific Method ““controlled” controlled” experimentexperiment- - designed to designed to

test the hypothesistest the hypothesis only two possible answers:only two possible answers:

1)1) hypothesis is righthypothesis is right

2)2) hypothesis is wronghypothesis is wrong We gather data and observations We gather data and observations

by doing the experimentby doing the experiment Modify hypothesis - repeat the cycleModify hypothesis - repeat the cycle

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Scientific MethodScientific Method We deal with We deal with variablesvariables, , or factors that can or factors that can

change.change. Two types: Two types:

1) 1) Manipulated variableManipulated variable (or independent (or independent variable) is variable) is the one that the one that wewe change change

2) 2) Responding variableResponding variable (or dependent (or dependent variable) is variable) is the one observed during the the one observed during the experimentexperiment

For results to be accepted, the experiment For results to be accepted, the experiment needs to always produce the same resultneeds to always produce the same result

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Outcomes over the long term…Outcomes over the long term… TheoryTheory (Model) (Model)

- - A set of A set of well-testedwell-tested hypotheses that give hypotheses that give an overall an overall explanationexplanation of some natural of some natural phenomenon – phenomenon – not able to be provednot able to be proved

Natural LawNatural Law (or Scientific Law) (or Scientific Law)

- - The same observation applies to manyThe same observation applies to many different systems; different systems; summarizessummarizes results results

- - an example would be:an example would be:

the Law of Conservation of Massthe Law of Conservation of Mass

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Law vs. TheoryLaw vs. Theory

A A lawlaw summarizes summarizes whatwhat has has happened.happened.

A A theorytheory (model) is (model) is an an attempt to explain attempt to explain whywhy it it happened happened – this changes as – this changes as new information is gathered.new information is gathered.

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Using your senses to obtain information

Hypothesis is a proposed explanation; should be based on previous knowledge; an “educated” guess

The procedure that is used to test the hypothesis

A well-tested explanation for the observations; cannot be proven due to new discoveries

Tells what happened

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Collaboration / CommunicationCollaboration / Communication When scientists share ideas by When scientists share ideas by

collaboration and communication, collaboration and communication, they they increase the likelihoodincrease the likelihood of a of a successful outcomesuccessful outcome

How is communication done?How is communication done? Is the Internet reliable information?Is the Internet reliable information?

–http://www.dhmo.orghttp://www.dhmo.org

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Section 1.4Section 1.4Problem Solving in ChemistryProblem Solving in Chemistry

OBJECTIVES:OBJECTIVES:–Identify two general steps in Identify two general steps in

problem solving.problem solving.–Describe three steps for Describe three steps for

solving numeric problems.solving numeric problems.–Describe two steps for solving Describe two steps for solving

conceptual problems.conceptual problems.

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Problem Solving in ChemistryProblem Solving in Chemistry We are faced with problems each We are faced with problems each

day, and not just in chemistryday, and not just in chemistry A solution (answer) needs to be foundA solution (answer) needs to be found Trial and Error may work sometimes?Trial and Error may work sometimes? But, there is a But, there is a methodmethod to problem to problem

solvingsolving that works better, and these that works better, and these are skills that no one is born knowing are skills that no one is born knowing – they need to be learned.– they need to be learned.

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Problem Solving in ChemistryProblem Solving in Chemistry Effective problem solving usually Effective problem solving usually

involves two general steps:involves two general steps:1)1) Developing a planDeveloping a plan2)2) Implementing that planImplementing that plan

The skills you use to solve a word The skills you use to solve a word problem in chemistry are NOT problem in chemistry are NOT different from those techniques different from those techniques used in shopping, cooking, or used in shopping, cooking, or planning a party.planning a party.

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Solving Numeric ProblemsSolving Numeric Problems MeasurementsMeasurements are an important part are an important part

of chemistry; thus many of our word of chemistry; thus many of our word problems involve use of mathematicsproblems involve use of mathematics–Word problems are Word problems are real life real life

problemsproblems, and sometimes more , and sometimes more information is presented than information is presented than needed for a solutionneeded for a solution

Following skills presented will help Following skills presented will help you become more successfulyou become more successful

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Solving Numeric ProblemsSolving Numeric Problems The three steps we will use for The three steps we will use for

solving a numeric word problem are:solving a numeric word problem are:

1)1) AAnalyzenalyze

2)2) CCalculatealculate

3)3) EEvaluatevaluate The following slides tell the meaning The following slides tell the meaning

of these three steps in detail.of these three steps in detail.

Let’s learn how

to ACE these numeric word problems!

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Solving Numeric ProblemsSolving Numeric Problems1)1) AnalyzeAnalyze:: this is the starting point this is the starting point

– Determine what are the Determine what are the known factorsknown factors, , and write them down on your paper!and write them down on your paper!

– Determine what is the Determine what is the unknownunknown. If it is . If it is a number, determine the a number, determine the unitsunits needed needed

– Plan how to relate these factors- Plan how to relate these factors- choose an equation; use table or graphchoose an equation; use table or graph

This is the This is the heartheart of successful problem of successful problem solving techniques – it is the solving techniques – it is the PLANPLAN

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Solving Numeric ProblemsSolving Numeric Problems2)2) Calculate:Calculate: perform the mathematicsperform the mathematics

– If your plan is correct, this is the If your plan is correct, this is the easiest step. easiest step.

– Calculator used? Do it correctly!Calculator used? Do it correctly!

– May involve May involve rearrangingrearranging an an equation algebraically; or, doing equation algebraically; or, doing some some conversionconversion of units to some of units to some other units.other units.

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Solving Numeric ProblemsSolving Numeric Problems3)3) Evaluate:Evaluate: – the finishing step – the finishing step

– Is it reasonable? Make sense? Is it reasonable? Make sense? Do an estimate for the answer, Do an estimate for the answer, and check your calculations.and check your calculations.

– Need to round off the answer?Need to round off the answer?– Do you need scientific notation?Do you need scientific notation?– Do you have the correct units?Do you have the correct units?– Did you Did you answer the questionanswer the question??

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Solving Conceptual ProblemsSolving Conceptual Problems Not all word problems in chemistry Not all word problems in chemistry

involve doing calculationsinvolve doing calculations Nonnumeric problems are called Nonnumeric problems are called

conceptual problemsconceptual problems – ask you to apply – ask you to apply concepts to a new situationconcepts to a new situation

Steps are:Steps are:1)1) Analyze and 2) SolveAnalyze and 2) Solve

Plan needed to link known to unknown, Plan needed to link known to unknown, but no checking units or calculationsbut no checking units or calculations

Do Do Conceptual Problem 2.1Conceptual Problem 2.1 on page 46 on page 46