Chapter 1Chapter 1““Introduction Introduction

to to Chemistry”Chemistry”

General ChemistryGeneral Chemistry

Section 1.1Section 1.1ChemistryChemistry

OBJECTIVES:OBJECTIVES:

–Identify Identify five traditional five traditional areasareas of study in chemistry. of study in chemistry.

Section 1.1Section 1.1ChemistryChemistry

OBJECTIVES:OBJECTIVES:

–Relate Relate purepure chemistry to chemistry to appliedapplied chemistry. chemistry.

Section 1.1Section 1.1ChemistryChemistry

OBJECTIVES:OBJECTIVES:

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

What is Chemistry?What is Chemistry?

Chemistry is the study of the Chemistry is the study of the composition of “matter” composition of “matter”

matter is anything with mass and matter is anything with mass and occupies space, its composition, occupies space, its composition, properties, and the changes it properties, and the changes it undergoes.undergoes.

Has a definite affect on everyday Has a definite affect on everyday life -life -

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

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 - Chemistry of living

thingsthings5)5) Physical ChemistryPhysical Chemistry- describes the - describes the

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

Boundaries not firm – they overlap and Boundaries not firm – they overlap and interactinteract

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

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

chemistry to chemistry to attain certain goalsattain certain goals, in , in fields like medicine, agriculture, and fields like medicine, agriculture, and manufacturing – leads to an manufacturing – leads to an applicationapplication * Nylon – Figure 1.3, * Nylon – Figure 1.3, page 9page 9

* Aspirin (C* Aspirin (C99HH88OO44) - to relieve pain) - to relieve pain

* Use of TECHNOLOGY * Use of TECHNOLOGY (benefit!)(benefit!)

Why Study Chemistry?Why Study Chemistry?

Everyone and everything around us Everyone and everything around us involves chemistry – explains our involves chemistry – explains our worldworld

What in the world isn’t Chemistry?What in the world isn’t Chemistry? Helps you make choices; helps Helps you make choices; helps

make you a better informed citizenmake you 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 What did we describe as “pure” and What did we describe as “pure” and

“applied” chemistry?“applied” chemistry?

Section 1.3Section 1.3Thinking Like a ScientistThinking Like a Scientist

OBJECTIVES:OBJECTIVES:

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

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 - noting and recording information and and recording information and factsfacts

hypothesishypothesis- a proposed - a proposed explanation for the observation; explanation for the observation; must be tested by an experimentmust be tested by an experiment

Steps in the Scientific MethodSteps in the Scientific Method1. Observations (uses your senses)1. Observations (uses your senses)

a)a) quantitative involves numbers = quantitative involves numbers = 9595ooFF

b)b) qualitative is word description = hotqualitative is word description = hot2. Formulating hypotheses (ideas)2. Formulating hypotheses (ideas)

- - possible explanation for the possible explanation for the observation, or “educated” guess observation, or “educated” guess

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

decidedecide whether the hypothesis is validwhether the hypothesis is valid

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

designed to test the hypothesisdesigned to test 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 Modify hypothesis - repeat the

cyclecycle

Scientific MethodScientific Method

We deal with We deal with variablesvariables, or factors , or factors that can change. Two types:that can change. Two types:1) 1) Manipulated variableManipulated variable (or independent (or independent

variable) is the one that variable) is the one that wewe change change

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

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

Outcomes over the long Outcomes over the long term…term…

TheoryTheory (Model) (Model)

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

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

Law vs. TheoryLaw vs. Theory

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

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