Welcome to Chem 1050 !!

1. Welcome to Chem 1050 !! Mark Fickenscher

2. Ch 1 Matter & Change

3. At the end of Chem 1050 you will look like this mad scientist 

4. Chemistry • The study of the composition of substances & the changes they undergo

5. Question: What isn’t Chemistry? • We live in a complex world!! • Ex: Car – 30 yrs ago what was it made of?

6. Car Example • Now what is a car made of? And why? • Another question: Has chemistry & science in general been “good” for humans? Why or why not?

7. Chemistry • It is a basic building block for: • Biology • Physics • Geology

8. Technology • What is it? • Defn: Application of knowledge for practical purposes. • Which came first: science or technology?

9. Technology • Examples: cooking food, pottery, metals, fermentation, dyes, drugs from plants. • No scientific understanding, just application of technology • What is a more modern example?

10. Technology • Ex from Roman Empire: viaducts, aquaducts – fresh water supply and sewage systems in Rome. • Pb water pipes – what was wrong with this?

11. Theory • Greeks didn’t test theories only stated them without proof. • A theory “explains” something in science. • Science grew slowly out of natural philosophy – speculated about nature.

12. Alchemy • Middle ages – scientists equally comfortable with alchemy and real science. • Alchemy – no documentation but elements discovered; precious metals, elixers

13. Alchemy • Technology provided instruments such as microscopes. • Frances Bacon (1561-1626) – philosopher and lawyer – science should be experimental and should enrich our lives.

14. Alchemy & Chemistry • By mid 20th century – a lot came true. • Medicines, fertilizers, insecticides, hybrids, clothing. • Was all of the above good?

15. Alchemy & Chemistry • Rachel Carson – 1962 book Silent Spring was about what famous chemical? • DDT • Also the introduction of detergents in the 1950’s

16. Alchemy & Chemistry • Science has lost its luster or has it? What do I mean by that? • Back to some history – by late 1800’s the world was on the verge of starvation due to population growth and limited food supply

17. Fritz Haber • German chemist, WWI worked on making ammonia easier and more productive for war effort. • Turned out his methods saved the world from starvation. How did he do it? • (Equation on board)

18. Back to Chemistry • Science is based on observations. • Can’t force nature to suit our ideas. • Data must be reproducible. • Hypothesis – guess or a test based on observations.

19. Back to Chemistry • Humanities – what is beauty? Truth? This is not science! • In science – hypotheses are testable. • Science by the way is not fair! • A beautiful idea can be destroyed by experiments or tests.

20. Back to Chemistry • Example: The earth is flat  • By late 1800’s most everything had been discovered according to the top scientists of the day. The world clanked or chunked along with huge machines.

21. Back to Chemistry • Max Planck was a young man from Germany who was deciding to become a physicist or a mathematician and he was told to do math! He was told that most everything had been discovered by then!

22. Back to Chemistry • And yet no one could tell you where a baby came from or how it got started! • Scientific Law – concise statement • Ex: Boyle’s Law P1V1= P2V2

23. Back to Chemistry • Scientific models help explain complicated things. • Example of containers of liquid and gas • Science has to control variables

24. Chemistry • Chemistry is a central science • Matter – stuff of everything • Mass – measure of quantity of something • Weight – force (gravity) - it changes

25. Chemistry • Physical Property – physical characteristic – doesn’t change the substance • MP, BP, color, hardness, odor • Chemical Property – how substance reacts with other substances or matter.

26. Chemistry • Name a chemical property. • Physical Change – alters the material without changing its composition • Examples

27. Chemistry • Chemical Property – changes the substance into something else – creates new substances • Rust • Making rubber

28. Chemistry • Substance – pure, definite, fixed composition • Ex: water, NaCl • Mixture – 2 or more substances • Each retains their ID • Can be separated by physical means.

29. States of Matter • Solid – definite shape and volume • Liquid – less tightly packed and almost incompressible • Gas – takes shape & volume of container • State also known as a “phase”

30. Example of States of Matter 

31. Air • Air – is it a substance? • It is a mixture of substances! • Homogeneous mixture – same throughout – uniform • Ex: jello, Kool-Aid

32. Mixtures • Air • Beef stew • Salt water • Heterogeneous mixture – not uniform • Ex: salad

33. More Examples: • Soil or dirt • Blood • Milk • Auto Tire • Which above are heterogeneous or homogeneous?

34. Examples of HomogeneousMixtures • Salt water • Air • Brass – Cu & Zn • Pewter – Sn & Pb

35. Homogeneous Mixtures • Special Name for above: Solutions • All solutions are homogeneous mixtures

37. Elements & Compounds • Physically separate mixtures into parts you get pure substances. • Elements – fundamental substance • Cannot be broken down into simplier substances

38. Compounds • Made up of 2 or more elements • Can be separated by chemical reactions only not physical change

39. Compounds • Fixed composition – chemically combined • Not a mixture! • H2O , CO2 , NaCl • Always the same proportion

40. Examples • Water • 88.8% oxygen • 11.2% hydrogen • Always

41. Examples • Carbon Dioxide • 27.3% carbon • 72.7% oxygen • Always

42. Chemical Symbols • H2O • Shorthand way of writing chemical formulas of compounds • Co vs CO element always has lower case 2nd letter (if used)

43. C12H22O11 • Sucrose • NaHCO3 • Sodium Hydrogen Carbonate • Otherwise known as baking soda

44. Symbol Rules • First letter is always capitalized • 2nd letter is always lower case (if used)

45. Each element represented by a symbol • Now over 118 (?) • 90 found naturally • 1/3 essential for life • Approx. 8 elements account for 98% mass of earth’s crust

46. Measurements • SI units • Kg, sec, Kelvin, mol • Exponential numbers • Metric handout and important units in metric system

47. Measurements • Know: • m = meter • K = Kilo = 103 meter • μ = micro =10-6 meter • cm = centimeter = 10-2 meter • mm = millimeter = 10-3 meter

48. Measurements • Know: • 1.06 qt = 1 L • 2.54 cm = 1 inch • 1 lb. = 454 grams • 1L = 1000 mL

50. Example of Metric vs English Systems 