Upload
doris-nicholson
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
Chemistry 100
Chemistry Appreciation
3 credits
http://course1.winona.edu/rreuter
R. Reuter
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