INTRODUCTION TO CHEMISTRYChapter 1

Section Overview• 2.1: Chemistry• 2.2: Chemistry Far and Wide • 2.3: Thinking Like a Scientist• 2.4: Problem Solving in Chemistry

CHEMISTRYSection 1.1

What is Chemistry?• Chemistry is the study of the composition of matter and

the changes that matter undergoes.• Matter is anything that has mass and occupies space.

Matter isn’t always visible (ex. Air).• All things, living and nonliving, are made of matter.• Chemistry, therefore, affects all aspects of life and most

natural events.

Areas of Study• Organic chemistry: the study of all chemicals with carbon

(ex. Chemicals in organisms)• Inorganic chemistry: the study of all chemicals without

carbon (ex. Chemicals in rocks)• Biochemistry: the study of the processes that take place in

organisms (ex. Photosynthesis and respiration)• Analytical chemistry: the study that focuses on the

composition of matter (ex. Measuring lead in drinking water)

• Physical chemistry: the study that deals with the mechanism, the rate, and the energy transfer that happens when matter undergoes a change (ex. Factors involved when ice melts)

Pure vs Applied Chemistry• Pure chemistry is simply the pursuit of chemical

knowledge (ex. Nylon was produced during research attempts to understand the structure of silk).

• Applied chemistry is research that is directed toward a goal or application (ex. Nylon research information was used to produce it on a commercial scale due to the limit of silk).

• Technology is an applied science which helps scientists do things more quickly or with less effort (ex. Machines).

Why Study Chemistry?• Chemistry can be useful in explaining the natural world,

preparing people for career opportunities, and producing informed citizens.

• Explaining the natural world: Why do apples turn brown after being exposed to air? Why do eggs change from runny to firm after being boiled, scrambled, or fried?

• Preparing for a career: Not just limited to becoming a chemist. Even firefighters must know which chemicals to use to fight different types of fires.

• Being an informed citizen: The amount of money given to certain areas of scientific research is voted on at elections. Cancer research and NASA are equally important.

CHEMISTRY FAR AND WIDESection 1.2

Materials• Chemists design materials to fit specific needs.• Inspiration can often be found in nature from two different

viewpoints: macroscopic and microscopic.• Macroscopic: the world of objects large enough to see

with the naked eye.• Microscopic: the world of objects that can only be seen

under magnification.• Ex: George de Mestral invented “hook-and-loop-tape”

which are used as fasteners in items like shoes and gloves. He got inspiration from burrs in the woods that stuck to his clothes and studied them underneath the microscope.

Energy• Chemists play an important role in finding ways to

conserve, produce, and store energy.• Conservation: Minimizing energy transfer/heat loss (ex.

Development of insulation in things like homes and freezers which help block the flow of heat).

• Production: The process of creating energy to be used (ex. Burning fossil fuels such as coal, petroleum, and natural gas and more recently plant fuel).

• Storage: Harvesting energy to be released later (ex. Rechargeable batteries).

Medicine and Biotechnology• Chemistry supplies the medicines, materials, and

technology that doctors use to treat their patients.• Medicines: Many drugs are effective because they interact

in a specific way with chemicals inside body cells (ex. Antibiotics, antacids, aspirins, etc.).

• Materials: Chemistry can supply materials to repair or replace lost body parts (ex. Artificial hips and knees made from metals and plastics).

• Biotechnology: Applying science to the production of biological products or processes (ex. Gene therapy).

Agriculture• Chemists help develop more productive crops and safer,

more effective ways to produce crops.• Productivity: Measuring the amount of food grown on a

given unit of land and trying to improve (ex. Testing soil to see if contains the right chemicals to grow crops and help conserve water).

• Crop protection: Chemicals to kill specific insects and other pests that could harm crops and limit production (ex. Using chemicals produced by certain insects to fight insect pests like pinworms in tomatoes).

The Environment• Chemists help to identify pollutants and prevent pollution.• Identifying pollutants: Learning which chemicals can

cause environmental damage as well as damage to individual organisms (ex. Studies done in 1971 revealed that lead, such as what was used in paints and pipes, is a dangerous pollutant which can cause to brain damage).

• Preventing pollution: Creating strategies to limit exposure to pollutants (ex. The use of lead in house paint was banned in 1978).

The Universe• To study the universe, chemists gather data from afar and

analyze matter that is brought back to Earth.• This allows chemists to compare the composition of

matter found in space to matter found on Earth.• The most studied piece of matter are moon rocks.• Some of the rocks found resemble those on Earth formed

by volcanoes.• This suggests that molten lava once covered the moon’s

surface.

THINKING LIKE A SCIENTISTSection 1.3

Alchemy• The word chemistry comes from alchemy.• Alchemists were around before chemists and developed

the tools and techniques for working with chemicals.• Alchemy had two sides: practical and mystical.• Practical alchemy: Focused on developing techniques for

working with metals, glass, and dyes.• Mystical alchemy: Focused on concepts like perfection.• Some tools alchemists developed include beakers, flasks,

tongs, and funnels• What alchemists lacked was a logical explanation for the

changes in matter they observed.

An Experimental Approach to Science

• The shift from alchemy to science occurred in the 1500s in Europe.

• In the 1700s, scientist by the name of Antoine-Laurent Lavoisier, transformed science of observation into science of measurement by creating a balance to measure mass.

• He also helped to settle an ongoing debate about how materials burn.

• He showed that oxygen is required for materials to burn.

The Scientific Method• The scientific method is a logical, systematic approach to

the solution of a scientific problem.• Steps involved:

• Making Observations• Testing Hypotheses• Developing Theories

• Making an observation can lead to a question.• Creating an answer to a question becomes the hypothesis. • An experiment is designed to test the hypothesis.• Once the results of the experiment have been repeated,

then a theory is developed which is a well-tested explanation for a broad set of observations.

Collaboration and Communication• In the scientific community, it is common for scientists to

work together.• When scientists collaborate, and communicate, they

increase the likelihood of a successful outcome.• Collaboration: A group of scientists working together to

reach a common goal (ex. Scientists from different fields coming together to work on cancer research).

• Communication: How scientists exchange and share information with one another (ex. Communication face to face through collaboration, publishing information in scientific journals, e-mail, phone, Internet etc.).

PROBLEM SOLVING IN CHEMISTRYSection 1.4

Skills Used in Solving Problems• Effective problem solving always involves developing a

plan and then implementing that plan.• Problem solving skills are not specific to science (ex.

Deciding which brands of food to buy at the supermarket comparing nutrition, price, etc.).

• When problem solving, you may utilize data tables, graphs, and other visual aids.

Solving Numeric Problems• Measurement is such an important part of chemistry,

therefore, a lot of word problems do involve math skills.• This process can be broken down into three steps:

analyze, calculate, evaluate.• Analyze: Identify what is unknown and what is known,

determine what units are used, make a plan for how to get the unknown.

• Calculate: Solve for the unknown which may involve unit conversions and/or rearranging formulas.

• Evaluate: Is the answer reasonable? Does it make sense? If not, reread the problem and try to figure out where you went wrong.

Solving Conceptual Problems• Some problems in chemistry simply ask you to apply the

concepts you are studying to a new situation instead of performing calculations.

• This process can be broken down into two steps: analyze and solve.

• Analyze: Still identify what is known and what is unknown and make a plan.

• Solve: Use your plan to solve for the unknown.