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Chapter 1“Introduction to

Chemistry”

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Section 1.1Chemistry

OBJECTIVES:–Identify five traditional areas of study in chemistry.

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Section 1.1Chemistry

OBJECTIVES:–Relate pure chemistry to applied chemistry.

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Section 1.1Chemistry

OBJECTIVES:–Identify reasons to study chemistry.

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What is Chemistry? Chemistry is the study of the

composition of “matter” – (matter is anything with mass and occupies space), its composition, properties, and the changes it undergoes.

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

Living and nonliving things are made of 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 Chemistry1) Analytical Chemistry- concerned with

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

with substances without carbon3) Organic Chemistry- essentially all

substances containing carbon4) Biochemistry- Chemistry of living things5) Physical Chemistry- describes the

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

Boundaries not firm – they overlap and interact

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What is Chemistry? Pure chemistry- gathers knowledge for

the sake of knowledge Applied Chemistry- is using chemistry

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

* Optical fibers (SiO2)* Aspirin (C9H8O4) - to relieve pain

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Why Study Chemistry? Everyone and everything around us

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

you a better informed citizen A possible career for your future Used to attain a specific goal What did we describe as “pure” and

“applied” chemistry?

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Why Study Chemistry?Figure 1.4, page 5

–What benefits do each of the pictures represent in improving our lives?

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

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Section 1.2Chemistry Far and Wide

OBJECTIVES:–Identify some areas of research affected by chemistry.

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Section 1.2Chemistry Far and Wide

OBJECTIVES:–Describe some examples of research in chemistry.

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Section 1.2Chemistry Far and Wide

OBJECTIVES:–Distinguish between macroscopic and microscopic views.

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Chemistry Far and WideChemists design materials to fit

specific needs – velcro (Patented in 1955)

perfume, steel, ceramics, plastics, rubber, paints, nonstick cooking utensils, polyester fibers

Two different ways to look at the world: macroscopic and microscopic

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Chemistry Far and WideEnergy – we constantly have

greater demands–We can conserve it; use wisely–We can try to produce more; oil

from soybeans to make biodiesel–fossil fuels, solar, batteries (that

store energy – rechargeable?), nuclear (don’t forget pollution!)

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Chemistry Far and Wide Medicine and Biotechnology-

–Supply materials doctors use to treat patients – spatial arrangements of protein molecules

–Synthesis of vitamin C, penicillin, aspirin (C9H8O4)

–alloys for artery transplants and hipbones –Gene technology -bacteria producing

insulin (DNA chemical structure)

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Chemistry Far and WideAgriculture

–Produce the world’s food supply–Use chemistry for better

productivity – soil, water, weeds–plant growth hormones–ways to protect crops; insecticides

(honeybees)

–disease resistant plants

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Chemistry Far and Wide The Environment

–both risks and benefits involved in discoveries- which outweights

–Pollutants need to be 1) identified and 2) prevented

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

–carbon dioxide, ozone, global warming

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- Pge 16

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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Section 1.3Thinking Like a Scientist

OBJECTIVES:–Identify the steps in the scientific method.

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Section 1.3Thinking Like a Scientist

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

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The Scientific MethodA logical approach to solving

problems or answering questions.Starts with observation- noting and

recording information and factshypothesis- a proposed

explanation for the observation; must be tested by an experiment

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

a) quantitative involves numbers = 95oF

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

- possible explanation for the observation, or “educated”

guess- “If [ I do this ], then [ this ] will happen.”

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

decide whether the hypothesis is valid

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Steps in the Scientific Method

4. Analysis (What happened )- what data did you obtain and what does it mean

5. Conclusion (the WHY) -You have two options for your conclusions:

based on your results, either (1) you CAN REJECT (2) you SUPPORT the hypothesis.

– This is an important point. You can not PROVE the hypothesis with a single experiment

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Scientific Method “controlled” experiment- designed to

test the hypothesis We gather data and observations by

doing the experiment Modify hypothesis - repeat the cycle

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Scientific Method We deal with variables, or factors that can

change. Two types:1) Manipulated variable (or independent

variable) is the one that we change2) Responding variable (or dependent

variable) is the one observed during the experiment

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

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Outcomes over the long term… Theory (Model)

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

Natural Law (or Scientific Law)- The same observation applies to many different systems; summarizes results

- an example would be: the Law of Conservation of Mass

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Law vs. Theory

A law summarizes what has happened.

A theory (model) is an attempt to explain why it happened – this changes as 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 / Communication When scientists share ideas by

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

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Problem Solving in Chemistry We are faced with problems each day,

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

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

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Problem Solving in Chemistry Effective problem solving usually

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

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

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Solving Numeric Problems Measurements are an important part

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

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

Following skills presented will help you become more successful

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Solving Numeric Problems The three steps we will use for

solving a numeric word problem are:

1) Analyze2) Calculate3) Evaluate

The following slides tell the meaning of these three steps in detail.

Let’s learn how to ACE these numeric word problems!

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Solving Numeric Problems1) Analyze: this is the starting point

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

– Determine what is the unknown. If it is a number, determine the units needed

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

This is the heart of successful problem solving techniques – it is the PLAN

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Solving Numeric Problems2) Calculate: perform the mathematics

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

– Calculator used? Do it correctly!– May involve rearranging an

equation algebraically; or, doing some conversion of units to some other units.

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Solving Numeric Problems3) Evaluate: – the finishing step

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

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

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Solving Conceptual Problems Not all word problems in chemistry

involve doing calculations Nonnumeric problems are called

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

Steps are:1) Analyze and 2) Solve

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

Do Conceptual Problem 2.1 on page 46

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