Chemistry 100

Chemistry Appreciation

3 credits

http://course1.winona.edu/rreuter

R. Reuter

rreuter@winona.edu

PA 330

457-5874

Why are you here?

Give some examples of chemistry in our world

1. Can you group any of the following?2. Which ones?3. Why did you group them together?

• Hiroshima Atomic bomb (1945)• Baking a cake• Antacid• Greenhouse gases/Global warming• Hot air balloon• Deep fat frying• Acrylamide gel separation (of proteins)• Oklahoma City bombing (1995)• Rotten eggs• Acid rain “eats” away statues

Where does the word Science come from?

Middle English, knowledge, learning,

from Old French, from Latin scientia,

from sciēns, scient-, present participle of scīre, to know;

[see skei- in Indo-European roots.]

American Heritage Dictionary

sci·ence   (sī'əns)    n. 

• Science  – The observation, identification, description, experimental

investigation, and theoretical explanation of phenomena. – Such activities restricted to a class of natural phenomena. – Such activities applied to an object of inquiry or study.

• Methodological activity, discipline, or study• An activity that appears to require study and method. • Knowledge, especially that gained through

experience. (i.e., empirical evidence) American Heritage Dictionary

• Science in the broadest sense refers to any system of objective knowledge. In a more restricted sense, science refers to a system of acquiring knowledge based on the scientific method, as well as to the organized body of knowledge humans have gained by such research

Wikipedia

What is Chemistry?

• Chemistry is the science that seeks to understand what matter does by studying what atoms and molecules do.

• Chemistry is the science that investigates the molecular reasons for those processes that are constantly occurring in our macroscopic world.

What is Chemistry?

• Chemistry is the science concerned with the characterization, composition and transformations of matter.

• Chemistry is the science which deals with matter: the structure and properties of matter and the transformations from one form of matter to another.

What is Chemistry?

• Chemistry is the study of the materials in the universe and the changes they undergo

• Chemistry is the study of matter and the changes it undergoes.

Form of Definitions

• A “term” is a NOUN that….(describe it)…

Chemistry is the study of matter andthe changes it undergoes.

• It is NOT “when” something happens.

Important Definitions:

• Matter is anything which has mass and occupies space.   

• Mass is a measure of the amount of matter. Mass does not change.

• Weight is a measure of the pull of gravity on matter. Weight changes, depending upon where it is measured.

Has chemistry been good for people?

Has chemistry been bad for people?

Should Compound A be banned?

• Irritant to body tissue.• Toxic by ingestion:

– 65 mg can be lethal.

• Target organs: – Central Nervous System, Heart

• Possible mutagen• Possible teratogen• Wear goggles, chemical-resistant gloves

when handling

Compound A

Should Compound B be banned?

• More addictive than cocaine or heroin• Alkaloid• Highly toxic• May be fatal if inhaled, ingested or absorbed

through skin• Effects:

– Headache, nausea, diarrhea, dizziness, vomiting

• Target organs:– Nervous tissue, GI system

• Possible teratogen

Compound B

Question: Should “Compound C” be banned?

Compound C:• is a good cleaning agent.• is a reasonably good coolant.• is important for some ethnic or religious groups• said may contribute to plant growth.

Question: Should “Compound C” be banned?

“Compound C” has been responsible for:• Respiratory failure and death when inhaled in

large amounts• Damage to skin or other body parts after

exposure to the solid• Severe burns when skin is exposed to the gas• Bone breakage after contact with the solid• Extreme toxicity (and even death) when

ingested in large amounts.

Compound C

Solid form of Compound C

• Compound A =

• Compound B =

• Compound C =

• What information is needed to help you decide about these substances?

Think of a “dangerous” situation

• Should you take a risk?

• Under what conditions?

Risk Analysis

Benefit is anything that has positive effect

Risk is anything that has negative effect

Need to weigh benefits against risks

Look at: Benefits = DQ = Desirability

Risks Quotient

Positive effect

DQ = Benefit / Risk ratio is high

Big Benefit

Small Risk

Negative effect

DQ = Benefit / Risk ratio is low

Small Benefit

Big Risk

Penicillin kills bacteria and saves the lives of people who might die from infectious diseases.

Do a risk analysis for using penicillin for society as a whole.

Some people have an allergy to penicillin.

Do a risk analysis for using penicillin for people who are allergic to penicillin.

Projected risk can be different for different populations

One individualA group of individualsSociety as a whole

Can we eliminate all risk?

What is a reasonable risk?

What is an acceptable risk?

Should we look at the costs of reducing or eliminating risk?

Need to balance risk and benefit----and cost

Science can provide information

Society decides what risk is acceptable

Laws have been enacted to provide reasonable protection to the public

Various approaches, but assume that risks cannot be totally eliminated

Frequently revised as new technology is developed

Balancing Risks vs. Benefits

*Attempt to come up with “reasonable” risk

--essentially a compromise.

*EPA also required to look at costs.

Technology-based Laws

Assume some risk is inevitable.

Use latest economically feasible technology to impose “standard” limits.

Examples

Environmental Protection AgencySafe Drinking Water Act (1974, 1986, 1996)Clean Air Act

Food and Drug AdministrationFood, Drug and Cosmetic Act (1938)

FDA had to prove substance was unsafeFood Additives Amendment (1958)

Food industry had to prove substance was safe

Delaney Amendment (1958)Cannot use any food additive found to induce cancer in man or in animals

Major Branches of Chemistry

Analytical:

What is it? How much is present?

Physical:

Explain why matter behaves the way it does.

Inorganic:

Compounds without Carbon

Organic:

Compounds that contain Carbon

(usually have Hydrogen as well)

Biochemistry:

Chemistry of living systems