“Introduction to
Chemistry”
Chemistry
 OBJECTIVES:
–Identify five traditional
areas of study in chemistry.
Chemistry
 OBJECTIVES:
–Relate pure chemistry to
applied chemistry.
Chemistry
 OBJECTIVES:
–Identify reasons to study
chemistry.
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.
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 Chemistry
Analytical Chemistry- concerned with
the composition of substances.
2) Inorganic Chemistry- primarily deals
with substances without carbon
3) Organic Chemistry- essentially all
substances containing carbon
4) Biochemistry- Chemistry of living things
5) Physical Chemistry- describes the
behavior of chemicals (ex. stretching);
involves lots of math!
Boundaries not firm – they overlap and interact
1)
- Page 8
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
* Nylon – Figure 1.3, page 9
* Aspirin (C9H8O4) - to relieve pain
* Use of TECHNOLOGY (benefit!)
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?
Chemistry Far and Wide
 OBJECTIVES:
–Identify some areas of
research affected by
chemistry.
Chemistry Far and Wide
 OBJECTIVES:
–Describe some examples
of research in chemistry.
Chemistry Far and Wide
 OBJECTIVES:
–Distinguish between
macroscopic and
microscopic views.
Chemistry Far and Wide
 Chemists
design materials to fit
specific needs – velcro (Patented in 1955)
on page 12
 perfume, steel, ceramics, plastics,
rubber, paints, nonstick cooking
utensils, polyester fibers
 Two different ways to look at the
world: macroscopic and
microscopic
Chemistry Far and Wide
– 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!)
 Energy
Chemistry Far and Wide
 Medicine
and Biotechnology–Supply materials doctors use to
treat patients
–vitamin C, penicillin, aspirin (C H O )
–materials for artery transplants
and hipbones
–bacteria producing insulin
9
8
4
Chemistry Far and Wide
 Agriculture
–Produce the world’s food supply
–Use chemistry for better
productivity – soil, water, weeds
–plant growth hormones
–ways to protect crops; insecticides
–disease resistant plants
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
- Page 16
Let’s 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.
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?
Thinking Like a Scientist
 OBJECTIVES:
–Describe how Lavoisier
transformed chemistry.
Thinking Like a Scientist
 OBJECTIVES:
–Identify three steps in the
scientific method.
Thinking Like a Scientist
 OBJECTIVES:
–Explain why collaboration
and communication are
important in science.
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
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
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!
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
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
Scientific Method




“controlled” experiment- designed to
test the hypothesis
only two possible answers:
1) hypothesis is right
2) hypothesis is wrong
We gather data and observations by
doing the experiment
Modify hypothesis - repeat the cycle
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

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
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.
- Page 22
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
Tells what happened
A well-tested explanation for
the observations; cannot be
proven due to new discoveries
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?
 Is the Internet reliable information?
–http://www.dhmo.org
Problem Solving in Chemistry
 OBJECTIVES:
–Identify two general steps
in problem solving.
Problem Solving in Chemistry
 OBJECTIVES:
–Describe three steps for
solving numeric problems.
Problem Solving in Chemistry
 OBJECTIVES:
–Describe two steps for
solving conceptual
problems.
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?
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.
 But,
Problem Solving in Chemistry


Effective problem solving usually
involves two general steps:
1) Developing a plan
2) 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.
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
Solving Numeric Problems

The three steps we will use for
solving a numeric word problem are:
1) Analyze
2) Calculate
3) Evaluate

Let’s learn how
to ACE these
numeric word
problems!
The following slides tell the meaning
of these three steps in detail.
Solving Numeric Problems
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 factorschoose an equation; use table or graph
This is the heart of successful problem
solving techniques – it is the PLAN
Solving Numeric Problems
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.
Solving Numeric Problems
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?
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