Chapter 1

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Chapter 1Introduction to Chemistry

• Pequannock Township High School
• Chemistry
• Mrs. Munoz

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Section 1.1Chemistry

• OBJECTIVES
• Identify five traditional areas of study in
  chemistry.
• Relate pure chemistry to applied chemistry.
• Identify reasons to study chemistry.

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What is Chemistry?

• Chemistry is the study of the composition of
  matter
• 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. The chemistry is shown as a chemical
equation (reaction equation)
C2H5OH 3 O2 ? 2 CO2 3 H2O Energy
Reactants ? Products
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5 Major Areas of Chemistry

• Analytical Chemistry concerned with the
  composition of substances
• Inorganic Chemistry primarily deals with
  substances without carbon
• Organic Chemistry essentially all substances
  containing carbon
• Biochemistry Chemistry of living things
• Physical Chemistry describes the behavior of
  chemicals (ex. stretching) involves lots of
  math!
• Boundaries of the areas of chemistry overlap and
  interact.

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What is Chemistry?

• Pure chemistry gathers knowledge for the sake of
  knowledge
• Applied Chemistry uses chemistry to attain
  certain goals, in fields like medicine,
  agriculture, and manufacturing. Applied chemistry
  leads to an application
• Nylon Figure 1.3, page 9
• Aspirin (C9H8O4) - to relieve pain

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Why Study Chemistry?

• Everyone and everything around us involves
  chemistry explains our world
• 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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Section 1.2Chemistry Far and Wide

• OBJECTIVES
• Identify some areas of research affected by
  chemistry.
• Describe some examples of research in chemistry.
• Distinguish between macroscopic and microscopic
  views.

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Chemistry Far and Wide

• Chemists design materials to fit specific needs
  velcro (page 12)
• Examples of chemistry 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 Wide

• Energy 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 (dont forget
  pollution!)

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Chemistry Far and Wide

• Medicine and Biotechnology-
• Supply materials doctors use to treat patients
• vitamin C, penicillin, aspirin (C9H8O4)
• materials for artery transplants and hipbones
• bacteria producing insulin

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Chemistry Far and Wide

• Agriculture
• Produce the worlds food supply
• Use chemistry for better productivity soil,
  water, weeds
• plant growth hormones
• ways to protect crops insecticides
• disease resistant plants

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Chemistry Far and Wide

• The Environment
• both risks and benefits involved in discoveries
• 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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Lets examine some information from a graph.
88.2
440,000
After lead was banned in gasoline and public
water supply systems, less lead entered the
environment.
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Chemistry Far and Wide

• The Universe
• Need to gather data from afar, and analyze matter
  brought back to Earth
• composition of the planets
• analyze moon rocks
• planet atmospheres
• life on other planets?

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Section 1.3Thinking Like a Scientist

• OBJECTIVES
• Describe how Lavoisier transformed chemistry.
• Identify three steps in the scientific method.
• Explain why collaboration and communication are
  important in science.

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Alchemy developed the tools and techniques for
working with chemicals

• The word chemistry comes from alchemy practiced
  in China and India since 400 B.C.
• Alchemy has two sides
• Practical techniques for working with metals,
  glass, dyes, etc.
• Mystical concepts like perfection gold was a
  perfect metal

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An Experimental Approach

• In the 1500s, a shift started from alchemy to
  science King Charles II was a supporter of the
  sciences
• Royal Society of London for the Promotion of
  Natural Knowledge
• Encouraged scientists to use more experimental
  evidence, and not philosophical debates

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Lavoisier

• In the late 1700s, Antoine Lavoisier helped
  transform chemistry from a science of observation
  to the science of measurement still used today
• He settled a long-standing debate about burning,
  which was
• Oxygen was required!

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The Scientific Method

• A logical approach to solving problems or
  answering questions.
• Starts with observation- noting and recording
  information and facts.
• hypothesis- a proposed explanation for the
  observation must be tested by an experiment.

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Steps in the Scientific Method

• 1. Observations (uses your senses)
• a) quantitative involves numbers 95oF
• b) qualitative is word description hot
• 2. Formulating hypotheses (ideas)
• - possible explanation for the
  observation, or educated guess
• 3. Performing experiments (the test)
• - gathers new information to help decide
• whether the hypothesis is valid

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Scientific Method

• controlled experiment- designed to test the
  hypothesis
• only two possible answers
• hypothesis is right
• hypothesis is wrong
• 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 change
• 2) 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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The procedure that is used to test the hypothesis
Using your senses to obtain information
Hypothesis is a proposed explanation should be
based on previous knowledge an educated guess
Tells what happened
A well-tested explanation for the observations
cannot be proven due to new discoveries
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Collaboration / Communication

• When scientists share ideas by collaboration and
  communication, they increase the likelihood of a
  successful outcome
• Collaboration Fig. 1.21, p. 24
• How is communication done?

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Section 1.4Problem Solving in Chemistry

• OBJECTIVES
• Identify two general steps in problem solving.
• Describe three steps for solving numeric
  problems.
• Describe two steps for solving conceptual
  problems.

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Problem Solving in Chemistry

• Problems exist 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. Problem solving skills need to be
  learned.

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Problem Solving in Chemistry

• Effective problem solving usually involves two
  general steps
• Developing a plan
• 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.
  Many chemistry word problems involve use of
  mathematics.
• Word problems are real life problems, and
  sometimes more information is presented than
  needed for a solution.
• The 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
• Analyze
• Calculate
• Evaluate
• The following slides tell the meaning of these
  three steps in detail.

Lets learn how to ACE these numeric word
problems!
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Solving Numeric Problems, Step 1

• 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 Problems, Step 2

• 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 Problems, Step 3

• 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
  numerical/definitive calculations
• Nonnumeric problems are called conceptual
  problems just apply concepts to a new situation
• Steps are
• Analyze
• Solve
• Plan needed to link known to unknown, but no
  checking units or calculations

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Conclusion of Chapter 1 Introduction to Chemistry