2. Chem 106 Practical Everyday Chemistry Dr. Ron Rusay Diablo Valley College Spring 2003

3. What’s in the box? Take a look at one of the boxes coming around. Write down a description of what is in the box.

4. Chem 106’s Homepage

5. Science, Mathematics, Chemistry & the World Around You  What is science?…. What is chemistry?  VOCABULARY: Key Terms/ Communication  Comparisons and Conversions : Ratios, Percent, Density  Mathematics / Arithmetic: Powers of Ten, Scientific Notation  Measurement & Units: (metric)  Matter : Classification & Properties © Copyright 1998-2003 R.J. Rusay

6. Observation: Perception Can more than one observation be correct?Can more than one observation be correct? What do you see?What do you see? Science relies on observation.

7. Science: Problem Solving Can you connect all of the dots with four straight lines without taking a pen or pencil from the surface?

8. Science: Problem Solving

9. Can there be more than one solution for the same problem? Of Course!

10. What’s in the box? Open the box. Describe what is in the box. The content of the boxes are different. How can you provide a single, “correct”, description of what’s in the box?

11. Ancient Science: The Greeks What is around us?

12. Science is driven by asking questions & making predictions. The Scientific Method is a way to develop answers.

13. Some Possible Steps in the Scientific Method  1. Observations ---- qualitative ---- quantitative  2. Formulating hypotheses ----possible explanation for the observation  3. Performing experiments ----gather new information to test whether the hypothesis is valid

15. Chemistry is the Study of Matter  Observed in all of its forms & behaviors.  Sub-categories Organic: carbon Inorganic: non-carbon Organometallic: Organic + Inorganic Analytical: What?, How much?, How pure? Biological / Biochemistry: living organisms Physical: energy, changes, rates Nuclear: the nucleus Environmental: interdisciplinary, eg. Oceanography © Copyright 1998-2003 R.J. Rusay Can mean the study of anything and everything! Can matter be observed at all times?

16. Modern Science & Chemistry Would this motivate you to pursue a career in science/chemistry?Would this motivate you to pursue a career in science/chemistry? Why would this “excite” a scientist, and what does dating have to to with it?Why would this “excite” a scientist, and what does dating have to to with it? http://www.mpg.de/news98/news20_98.htm

17. How do we know how old things are ?… like sloth dung Dating! Radiocarbon dating that is. It allows determining the age of biological artifacts like dung up to about 40,000 years old. This method provides an direct measurement of age. How do we determine our own age?How do we determine our own age? Can this work for anyone or any animal that ever lived?Can this work for anyone or any animal that ever lived?

18. Match the years in the second column with choices from the first column B C E I F L K G D A H J

19. Types of Basic Measurements MASS (weight) LENGTH VOLUME (occupied space) TEMPERATURE TIME Qualitative vs. Quantitative Eg. Qualitative: Old (dung) vs. Young (you?) Quantitative: 38,000 year old (dung) vs. a 19 year old (you?) © Copyright 1998-2003 R.J. Rusay

20. What is the length of the rod? Different measurement tools give different numbers: Which ruler is better? Did the Hubble space telescope use English or metric units in its construction? …..navigating the Mars Climate Orbiter?

21. Representations of Measurements: An example of a relative comparison using length to represent time TIME: 38,000 year old (dung) vs. 20 year old student LENGTH: Use lines to represent the respective ages that can be easily drawn on the classroom’s blackboard. Let 1 inch equal some period of time: 1 yr, 5 yr, 10yr, 100yr, 1000yr. (Select an appropriate one.) 38,000 year old (dung) vs. 20 year old student © Copyright 1998-2003 R.J. Rusay

22. Representations of Measurements An example of a relative comparison using length to represent time TIME: LENGTH; 38,000 year old (dung) vs. 20 year old student 1 in= 1 yr: dung = 38,000 in (> 1/2 mile) - student = 20 in 1 in= 5 yr: dung = 7,600 in (> 2 football fields) - student = 4 in 1 in= 10 yr: dung = 3,800 in (> 100 yds) - student = 2 in 1 in= 100 yr: dung = 380 in ( 31.6 feet) - student = 0.2 in 1 in= 1000 yr: dung = 38 in ( 3.16 feet) - student = 0.02 in © Copyright 1998-2003 R.J. Rusay

23. Representations of Measurements An example of a relative comparison using length to represent time TIME: LENGTH; 38,000 year old (dung) vs. 20 year old student 1 in= 1 yr: dung = 38,000 in (> 1/2 mile) - student = 20 in 1 in= 5 yr: dung = 7,600 in (> 2 football fields) - student = 4 in 1 in= 10 yr: dung = 3,800 in (> 100 yds) - student = 2 in 1 in= 100 yr: dung = 380 in ( 31.6 feet) - student = 0.2 in 1 in= 1000 yr: dung = 38 in ( 3.16 feet) - student = 0.02 in © Copyright 1998-2003 R.J. Rusay

24. Volume (Liquid Measurement Tools)

26. Relative Temperature Scales

27. Temperature

28. Chemistry in your car: Airbags Count how many words are new to you. A) ZeroB) 1-5C) 6-10D) >10

29. Volumes of regular shapes h V = l x w x h V = s 3

30. Volume of an object (any shape) by displacement What is the volume of the jade?

31. Conversion Factor Method (Dimensional Analysis) Qualitative Descriptions vs. Quantitative Use exact numbers / “scale factor” UNITS A Bookkeeping Method: Example ___ ft___in --------> ? m (1 ft = 12 in; 2.54 cm = 1 in; 100 cm = 1 m) ___ft x 12 in/ft + ___in = ___in ___in x 2.54 cm/in x 1 m/100cm = ___m © Copyright 1998-2003 R.J. Rusay

32. Density http://www.density.com/what.htm http://www.density.com/what.htm Density = Mass / Volume [g/mL or g/cm 3 ; g/L] Least dense man-made solid substance: Aerogel, D = 3.025 x 10 -3 g/cm 3 http://eande.lbl.gov/ECS/Aerogels/satoc.htm http://stardust.jpl.nasa.gov/spacecraft/aerogel.html D air = 1.22 x 10 -3 g/cm 3 (1.22 g/L) Densest known substance: a White Dwarf http://antwrp.gsfc.nasa.gov/apod/ap961203.html © Copyright 1998-2003 R.J. Rusay

33. Calculate the density [D = ? g/cm 3 ] of a White Dwarf. 1.0 teaspoon has a mass of 3.0 T (metric tons). (1 T = 1,000 kg; 1 kg = 1000g; tsp = 14.8 mL; 1 mL = 1 cm 3 ) Conversion Factors in red are among the ones that you must know from memory.

34. Percent A comparison based on normalization to 100. George Washington University, 1995: 64 unsealed addressed envelopes with $10 in each were dropped on campus in different classrooms. In economics 18 of 32 were mailed back, in [business, history and psychology] 10 of 32 were mailed. What is the percent for each of the 2 groups of students? © Copyright 1998-2003 R.J. Rusay

35. Percent Continued The Professor conducting the study received 43.75% of the original $640 in the mail. How much did he receive? How many of you would mail the envelop presuming no one knows you found it? One student mailed an empty envelop with the return address: Mr. IOU, 1013 Indebted Lane, Bankrupt City, MS (WSJ 1/18/95) © Copyright 1998-2003 R.J. Rusay

36. Chemistry & Matter: Properties & States Physical vs. Chemical Properties Solid (s), Liquid (l), Gas (g) Homogeneous vs. Heterogeneous Mixtures Organization of atoms/molecules: atoms/elements -> molecules/compounds Extensive vs. Intensive Properties Varies with amount (extensive) or does not vary with amount (intensive) © Copyright 1998-2003 R.J. Rusay

37. Chemistry & Matter (Chemicals)  How many different chemicals do you think have been reported in the scientific literature? A) 100,000 B) 1,000,000 C) 10,000,000 D) 100,000,000 E) 1,000,000,000 http://www.cas.org/18million.html

38. Properties & States of Matter Physical vs. Chemical Properties Solid (s), Liquid (l), Gas (g) Homogeneous vs. Heterogeneous Mixtures Organization of atoms/molecules: atoms/elements -> molecules/compounds Extensive vs. Intensive Properties © Copyright 1998-2003 R.J. Rusay

39. Organization of Matter

40. States of Matter

42. Mass and Volume Measurement