Introduction to Chemistry

1
Chapter 1

• Introduction to Chemistry

2
Chemistry

• What is
• A scientist?
• Anyone who is curious about something.
• A chemist?
• Anyone who is curious about chemistry.
• A chemical?
• A substance produced by or used in a chemical
  process.
• Any substance that has a definite composition.
• Everything is made of chemicals.
• Chemistry?
• The study of the composition of matter and the
  changes that matter undergoes.
• Matter?
• Anything that has a mass and occupies space (has
  a volume).

3
Chemistry

• Chemistry is called the central science because
  it touches many other scientific fields.
• Ex Agriculture, Electronics, Biology, Medicine,
  Environmental Science, Computer Science,
  Engineering, Geology, Physics, etc.
• There are seven areas of study in chemistry
  Analytical, Biochemistry, Inorganic, Nuclear,
  Organic, Physical, and Theoretical.

4
Chemistry

• Analytical The area of study that focuses on the
  composition of matter.
• Biochemistry The study of processes that take
  place in organisms.
• Inorganic The study of chemicals that, in
  general, do not contain carbon.
• Nuclear The study of radioactivity.
• Organic The study of all chemicals containing
  carbon.
• Physical The area that deals with the mechanism,
  the rate, and the energy transfer that occurs
  when matter undergoes a change.
• Theoretical The use of mathematics and computers
  to design and predict the properties of new
  compounds.

5
Chemistry

• The boundaries between these seven areas are not
  firm.
• A chemist is likely to be working in more than
  one area of chemistry at any given time.
• Some chemists enjoy doing research on fundamental
  aspects of chemistry, which is called pure
  chemistry.
• Pure Chemistry The pursuit of chemical knowledge
  for its own sake.
• Most chemists do research that is designed to
  answer a specific question, which is known as
  applied chemistry.
• Applied Chemistry Research that is directed
  toward a practical goal or application.
• In practice, pure and applied chemistry are often
  linked.
• Pure research can lead directly to an
  application, but an application can exist before
  research is done to explain how it works.
• Ex Nylon and Aspirin.

6
Chemistry

• The development of nylon and the use of aspirin
  to prevent heart attacks belong to a system of
  applied science called technology.
• Technology The means by which a society provides
  its members with those things needed and desired.
• Technology allows humans to do some things more
  quickly or with less effort.
• It allows people to do things that would be
  impossible without technology.
• Ex Travel to the moon, Mars, etc.

7
Chemistry

• Why study chemistry?
• Chemistry can be useful in explaining the natural
  world, preparing people for career opportunities,
  and producing informed citizens.
• Ex
• Why do apples turn brown upon exposure to air?
• Why does the texture of eggs change when they are
  cooked?
• Why does water expand when it freezes?
• Do firefighters need to know anything about
  chemistry?
• Do farmers need to know anything about chemistry?
• Do photographers need to know anything about
  chemistry?
• Do you, as a citizen, need to know anything about
  factories and industries in your area?
• Where does all the money come from for research?

8
Which field of science studies the composition
and structure of matter?

• Physics
• Biology
• Chemistry
• Geology

9
The study of chemicals that, in general, do not
contain carbon is traditionally called what type
of chemistry?

• Bio
• Inorganic
• Physical
• Analytical

10
Which of the following would a chemist be most
likely to study?

• A leaf floating on water.
• A leaf changing color in autumn.
• A leaf being blown by the wind.
• A leaf being eaten by insects.

11
Which of the following best describes an example
of pure chemistry?

• Testing the effects of lower concentrations of a
  drug on humans.
• Studying chemicals containing carbon.
• Developing a cure for osteoporosis.
• Finding an antidote for a new strain of virus.

12
Which of the following statements is false?

• Knowledge of chemistry allows the public to make
  informed decisions.
• Studying chemistry ensures that officials make
  correct choices in funding technology.
• Knowledge of chemistry helps prepare people for
  careers in soil science.
• Chemistry explains many aspects of nature.

13
Chemistry Far and Wide

• Chemists design materials to fit specific needs.
• Example George de Mastral - Velcro
• There are two different ways to look at the
  world.
• Macroscopic The world of objects that are large
  enough to see with the unaided eye.
• Microscopic The world of objects that can be
  seen only under magnification.
• Both terms share the same root scop which means
  to look at in Greek.
• Macro Makr (Greek) large
• Micro Mikr (Greek) small

14
Which of the following can be observed only in a
microscopic view?

• Foam insulation.
• X-ray of a knee joint.
• Shape of a soybean plant.
• Structure of a muscle cell.

15
Chemistry Far and Wide

• There are many different areas of research in
  chemistry
• Examples Energy, Medicine, Biotechnology,
  Agriculture, the Environment, the Universe, etc.
• Your text discusses each on of these in depth, as
  we discuss them, visualize a topic that you would
  like to investigate.
• Energy
• Chemists play an essential role in finding ways
  to conserve energy (insulation), produce energy
  (Ethanol/Biodiesel), and store energy (batteries).

16
Which of the following is not an example of
chemistry research in the main area of energy?

• Producing hook-and-loop tape.
• Determining the usefulness of oil from soybean
  plants.
• Developing rechargeable batteries.
• Studying the effects of insulation.

17
Chemistry Far and Wide

• Medicine and Biotechnology
• Chemistry supplies the medicines
  (Prescription/Nonprescription), materials
  (artificial limbs/organs), and technology (Human
  Genome Project) that doctors use to treat their
  patients.
• Biotechnology Applies science to the production
  of biological products or processes (Gene
  Therapy).

18
Chemistry Far and Wide

• Agriculture
• Chemists help to develop more productive crops
  (more edible food/drought and insect resistant),
  and safer, more effective ways to protect crops
  (Nonspecific chemicals vs. Specific chemicals).
• The Environment
• Chemists help to identify pollutants (lead) and
  prevent pollution (bans in 1978 for leaded paint
  and 1986 for leaded gasoline/water pipes).

19
Chemistry Far and Wide

• Questions
• What percentage of children had elevated lead
  levels in the 1970s?
• If a percentage point equals 200,000 children,
  how many children had elevated lead levels in
  2000?
• Explain the dramatic drop in the percentage of
  children affected by lead poisoning between 1980
  and 1988.

20
Chemistry Far and Wide

• The Universe
• To study the universe, chemists gather data from
  afar (i.e. the Moon, Mars, etc.) and analyze
  matter that is brought back to Earth (what are
  the made of?).

21
Which of the following is an example of a current
research focus in chemistry?

• Development of smoke detectors for common use.
• Using hook-and-loop tape in the clothing
  industry.
• Applying gene therapy to treat certain diseases.
• Studying coal combustion as an energy source.

22
Thinking Like a Scientist

• The word chemistry comes from alchemy.
• Alchemists developed the tools and techniques for
  working with chemicals.
• Ex Beakers, flasks, tongs, funnels,
  mortar/pestle, etc.
• Practical alchemy focused on developing the
  techniques for working with metals, glass, and
  dyes.
• Mystical alchemy focused on concepts like
  perfection (i.e. gold).
• Alchemists did not provide a logical set of
  explanations for the changes in matter that they
  observed.

23
Thinking Like a Scientist

• In the late 1700s, Antoine-Laurent Lavoisier
  revolutionized the science of chemistry.
• Lavoisier helped to transform chemistry from a
  science of observation to the science of
  measurement that it is today.
• Lavoisier designed a balance that could measure
  mass to the nearest 0.0005 grams.
• Lavoisier also settled a long standing debate
  about how materials burn.
• He showed through experiments that oxygen was
  required for materials to burn, not phlogiston, a
  substance within a material that caused it to
  burn.

24
Which of the following was a major contribution
to chemistry by Antoine Lavosier?

• He showed that oxygen is required for material to
  burn.
• He demonstrated the presence of phlogiston in
  air.
• He encouraged scientists to form explanations
  based on philosophical arguments.
• He developed the science of alchemy.

25
Thinking Like a Scientist

• In all branches of science, scientists use the
  scientific method to solve difficult problems.
• The scientific method is a logical, systematic
  approach to the solution of a scientific problem.
• Steps to the scientific method include making
  observations, testing hypotheses, and developing
  theories.
• Observation is information that you have obtained
  through your senses, and it often involves a
  question.

26
Thinking Like a Scientist

• Hypotheses are proposed explanations for an
  observation.
• A testable statement.
• Experiments are procedures that are used to test
  hypotheses.
• When you design an experiment, you deal with
  variables, or factors that can change.
• There are two different types of variables
• Manipulated Variable The variable that you
  change during an experiment (independent
  variable).
• Responding Variable The variable that is
  observed during an experiment (dependent
  variable).
• For an experiment to be accepted, the experiment
  must produce the same results no matter how many
  times it is repeated, or who is conducting the
  experiment.

27
Thinking Like a Scientist

• Theories are well-tested explanations for a broad
  set of observations.
• Ex The Big Bang Theory, Theory of Evolution,
  etc.
• In chemistry, theories can either address the
  fundamental structure of matter, or they allow
  you to predict the behavior of matter.
• Theories leave the door open for the possibility
  of change in the future as new observations are
  made.

28
Thinking Like a Scientist

• Scientific Laws are concise statements that
  summarize the results of many observations and
  experiments.
• I.E. Law of Gravity, Law of Conservation of
  Matter, Law of Conservation of Energy, etc.
• A law doesnt try to explain the relationship it
  describes, that explanation requires a theory.

29
One characteristic of a scientific theory is that

• It can never be proved.
• It can be proved.
• It cannot be modified.
• It summarizes a set of observations.

30
A theory is a

• Proposed explanation for a broad set of
  observations.
• Well-tested explanation for a broad set of
  observations.
• Summary of the results of many observations.
• Procedure used to test a proposed hypothesis.

31
Which step in the scientific method requires you
to use your senses to obtain information?

• Revising a hypothesis.
• Designing an experiment.
• Making an observation.
• Stating a theory.

32
The variable that is observed during an
experiment is called what type of variable?

• Independent.
• Manipulated.
• Controlling.
• Responding.

33
Thinking Like a Scientist

• When scientists collaborate and communicate, they
  increase the likelihood of a successful outcome.
• Collaboration is a process defined by the
  recursive interaction of knowledge and mutual
  learning between two or more people who are
  working together toward a common goal.
• Collaboration is not always a smooth process as
  conflicts can arise.
• Communication is a process that allows beings -
  in particular humans - to exchange information by
  several methods.
• I.E. The internet, phones, face-to-face, books,
  journals, etc.

34
Collaboration and communication are important in
science because

• Most research problems are not very complex.
• Most scientists have the knowledge to solve any
  scientific problem.
• They increase the likelihood of a successful
  outcome.
• They keep scientists from having to repeat
  experiments.

35
Problem Solving in Chemistry

• Effective problem solving always involves
  developing a plan and then implementing that
  plan.
• The steps for solving a numeric word problem are
  analyze, calculate, and evaluate.
• Analyze What is known? What is unknown? What is
  the plan? Diagram? Table? Graph?
• Calculate Equations? Conversions?
• Evaluate Is the answer reasonable? Correct
  units? Correct number of significant figures?
  Scientific notation?
• The steps for solving a conceptual problem are
  analyze and solve.

36
Problem Solving in Chemistry

• Example
• If your heart beats at an average of 72 times per
  minute, how many times will your heart beat in an
  hour? In a day?

37
Problem Solving in Chemistry

• Example
• You are visiting Indianapolis for the first time.
  Because it is a nice day, you decide to walk from
  the Indiana State Capital to the Murat Centre for
  an afternoon performance. According to the map ,
  the shortest route from the capital to the
  theater is 8 blocks. How many minutes will the
  trip take if you can walk one mile in 20 minutes?
  Assume that 10 short city blocks equals 1 mile.

38
Problem Solving in Chemistry

• Example
• On the average, a baseball team wins two out of
  every three games it plays. How many games will
  this team lose in a 162-game season?

39
Problem Solving in Chemistry

• Example
• How many days would it take you to count a
  million pennies if you could count one penny each
  second?

40
Which of these steps should always be followed
for effective problem solving?

• Buying a larger quantity of material than
  estimated.
• Performing metric conversions.
• Developing a plan and then implementing the plan.
• Using a trial-and-error approach and then
  evaluating.

41
The step that usually comes last in solving
numeric problems is

• Calculate.
• Measure.
• Evaluate.
• Analyze.

42
How do conceptual problems differ from numeric
problems?

• Solutions to conceptual problems involve
  analysis, while numeric solutions do not.
• Logic is not usually involved in solving numeric
  problems.
• A plan is necessary to solve numeric problems,
  but is not necessary for conceptual problems.
• Solutions to conceptual problems normally do not
  involve calculations.