1. HSTMr. Watson Chapter 1 Chemistry and Measurement

2. HSTMr. Watson Chemistry What is it? Why do we study it?

3. HSTMr. Watson Physical States solid – fixed volume and shape liquid – fixed volume – shape of container, horizontal top surface gas – takes shape and volume of container liquid crystal – some characteristics of solid and some of liquid states

4. HSTMr. Watson Modern Chemistry: A Brief Glimpse

5. HSTMr. Watson Air Bags: How Do They Work?

6. HSTMr. Watson Science and the Ozone Layer For more information about the Ozone Layer: Ozone Depletion – http://www.epa.gov/ozone/ Thickness of ozone layer – http://jwocky.gsfc.nasa.gov/teacher/ozone_overhead.html Memphis: +35 latitude -90 longitude

7. HSTMr. Watson Matter has mass mass vs. weight occupies space

8. HSTMr. Watson Scientific Method Experiment Results Hypothesis – further experiments – refine the hypothesis Theory – experiments to test the theory – refine the theory

9. HSTMr. Watson Law of Conservation of Mass In an ordinary chemical reaction matter is neither created nor destroyed. The sum of the masses of the reactants equals the sum of the masses of the products.

10. HSTMr. Watson Properties of Matter Extensive Property depends on specific sample under investigation examples: – mass and volume Intensive Property identical in all samples of the substance examples: – color, density, melting point, etc.

11. HSTMr. Watson Physical Property one that can be observed without changing the substances present in the sample changes in physical properties of substances

12. HSTMr. Watson Chemical Property the tendency to react and form new substances

13. HSTMr. Watson Chemical Reaction reactants undergo chemical change to produce products sucrose ---> carbon + water reactant products

14. HSTMr. Watson Chemical Reaction Reactions are indicated by: evolution of a gas change of color formation of a precipitate

15. HSTMr. Watson Law of Definite Proportions All samples of the same pure substance always contain the same elements in the same proportions by weight

16. HSTMr. Watson Pure Substances Elements Compounds

17. HSTMr. Watson Mixtures Heterogeneous uneven texture Homogeneous (Solution) sample uniform throughout

18. HSTMr. Watson

19. HSTMr. Watson Separation of Mixtures filtration distillation chromatography

20. HSTMr. Watson Filtration separate solids by differences in melting points separate solids by differences in solubility (fractional crystallization) mechanical separation such as in Fig. 1.11 page 13.

21. HSTMr. Watson Distillation separation by differences in boiling point (fractional distillation) – distillate – distillation fractionating column - part of apparatus where separation occurs

22. HSTMr. Watson

23. HSTMr. Watson Chromatography liquid-column paper thin-layer (TLC) gas HPLC electrophoresis (DNA mapping)

24. HSTMr. Watson Column Chromatography

25. HSTMr. Watson Paper Chromatography of Inks

26. HSTMr. Watson

27. HSTMr. Watson Uncertainty in Measurements Accuracy closeness to true value vs Precision reproducibility

28. HSTMr. Watson Accurate and/or Precise?

29. HSTMr. Watson Accurate and/or Precise?

30. HSTMr. Watson Significant Figures Rules for determining which digits are significant: All non-zero numbers are significant Zeros between non-zero numbers are significant Zeros to the right of the non-zero number and to the right of the decimal point are significant Zeros before non-zero numbers are not significant

31. HSTMr. Watson Significant Figures Examples: Railroad Track Scale 70,000,000 g + 500,000 g 7.00 x 10 7 g (scientific notation) 7.00 E 7 g (engineering notation) 3 significant figures

32. HSTMr. Watson Significant Figures Examples: Regular Lab Balance 1,000 g + 0.1 g 1.0000 x 10 3 g 5 sig. fig. 400 g + 0.01 g 4.0000 x 10 2 g 5 sig. fig. 100 + 0.001 g 1.00000 x 10 2 g 6 sig.fig.

33. HSTMr. Watson Rules for Mathematics Multiplication and Division For multiplication and division, the number of significant figures used in the answer is the number in the value with the fewest significant figures. 2 sig.fig.;3 sig. fig. => 2 sig. fig. 4 sig. fig.; = 2.0 x 10 2 (2075)*(14) ---------------- (144)

34. HSTMr. Watson Rules for Mathematics Addition and Subtraction For addition and subtraction, the number of significant figures used in the answer is determined by the piece of data with the fewest number decimal places. 4.371 302.5 -------- 306.8

35. HSTMr. Watson Rules for Mathematics Addition and Subtraction For addition and subtraction, the number of significant figures used in the answer is determined by the piece of data with the fewest number decimal places. 4.371 302.5 -------- 306.8

36. HSTMr. Watson Rules for Mathematics Addition and Subtraction For addition and subtraction, the number of significant figures used in the answer is determined by the piece of data with the fewest number decimal places. 4.371 (I truncate extra data) 302.5 -------- 306.8

37. HSTMr. Watson Exact Numbers conversion factors should never limit the number of significant figures reported in answer 12 inches = 1 foot

38. HSTMr. Watson Round Off Chemistry is an inexact science all physical measurements have some error thus, there is some inexactness in the last digit of any number use what ever round-off procedure you choose reasonably close answers accepted

39. HSTMr. Watson Measurement and Units length - meter volume - liter mass - gram

40. HSTMr. Watson Important Metric Unit Prefixes deci -- 1/10* centi -- 1/100* milli -- 1/1000* nano -- 1/1,000,000,000 kilo -- 1000*

41. HSTMr. WatsonLiter 1 liter = 1 decimeter 3 by definition where 1 decimeter = 10 centimeters therefore 1 liter = (10 centimeters) 3 or 1 liter =1000 cm 3 =1000 mL

42. HSTMr. Watson Millimeter 1 millimeter = 1/1000 meter 1000 millimeter = 1 meter 1000 mm = 1 m

43. HSTMr. Watson Nanometer 1 nanometer = 1/1,000,000,000 meter 1,000,000,000 nanometer = 1 meter 1,000,000,000 nm = 1 m

44. HSTMr. Watson Liter 1 liter = 1 decimeter 3 1 liter = 1000 milliliters 1 L = 1000 mL 1 mL = 0.001 L

45. HSTMr. Watson Milligram 1 milligram = 1/1000 gram 1 mg = 0.001 g

46. HSTMr. Watson Kilogram 1 kilogram = 1000 gram 1 g = 0.001 kg 1 mg = 0.000001 kg 1 kg = 1,000,000 mg

47. HSTMr. Watson Conversion of Units 1 in = 2.54 cm

48. HSTMr. Watson Temperature Scales: Fahrenheit Rankin – absolute scale using Fahrenheit size degree Celsius Kelvin – absolute scale using Celsius size degree

49. HSTMr. Watson

50. HSTMr. Watson Comparison of Temperature Scales

51. HSTMr. Watson Temperature Relationships C = 100/180 * (F - 32) F = (180/100)*C + 32 K = C + 273.15 - 40 o F = - 40 o C

52. HSTMr. Watson If the temperature of the room goes from 20 degrees C to 40 degrees C, the ambient thermal energy – doubles – is halved – increases by less than 10%

53. HSTMr. Watson Density Mass per unit of volume Mass equals volume times density Volume equals mass divided by density

54. HSTMr. Watson Problem Solving by Factor Label Method state question in mathematical form set equal to piece of data specific to the problem use conversion factors to convert units of data specific to problem to units sought in answer

55. HSTMr. Watson Example How many kilometers are there in 0.200 miles?

56. HSTMr. Watson Example How many kilometers are there in 0.200 miles? state question in mathematical form #km

57. HSTMr. Watson Example How many kilometers are there in 0.200 miles? set equal to piece of data specific to the problem #km = 0.200 miles

58. HSTMr. Watson Example How many kilometers are there in 0.200 miles? use conversion factors to convert units of data specific to problem to units sought in answer #km = (0.200 miles) * (5280 ft/mile)

59. HSTMr. Watson Example How many kilometers are there in 0.200 miles? cancel units #km = (0.200 miles) * (5280 ft/mile)

60. HSTMr. Watson Example How many kilometers are there in 0.200 miles? add another conversion factor #km = (0.200)*(5280 ft) *(12 in/ft)

61. HSTMr. Watson Example How many kilometers are there in 0.200 miles? cancel units #km = (0.200)*(5280 ft) *(12 in/ft)

62. HSTMr. Watson Example How many kilometers are there in 0.200 miles? #km = (0.200)*(5280)*(12 in)

63. HSTMr. Watson Example How many kilometers are there in 0.200 miles? add still another conversion factor #km = (0.200)*(5280)*(12 in) *(2.54 cm/in)

64. HSTMr. Watson Example How many kilometers are there in 0.200 miles? cancel units #km = (0.200)*(5280)*(12 in) *(2.54 cm/in)

65. HSTMr. Watson Example How many kilometers are there in 0.200 miles? #km = (0.200)*(5280)*(12)*(2.54 cm)

66. HSTMr. Watson Example How many kilometers are there in 0.200 miles? add still another conversion factor #km = (0.200)*(5280)*(12)*(2.54 cm) *(1 m/100 cm)

67. HSTMr. Watson Dr. S. M. Condren Example How many kilometers are there in 0.200 miles? cancel units #km = (0.200)*(5280)*(12)*(2.54 cm) *(1 m/100 cm)

68. HSTMr. Watson Dr. S. M. Condren Example How many kilometers are there in 0.200 miles? #km = (0.200)*(5280)*(12)*(2.54) *(1 m/100)

69. HSTMr. Watson Example How many kilometers are there in 0.200 miles? add still another conversion factor #km = (0.200)*(5280)*(12)*(2.54) *(1 m/100)*(1 km/1000 m)

70. HSTMr. Watson Example How many kilometers are there in 0.200 miles? cancel units #km = (0.200)*(5280)*(12)*(2.54) *(1 m/100)*(1 km/1000 m)

71. HSTMr. Watson Example How many kilometers are there in 0.200 miles? #km = (0.200)*(5280)*(12)*(2.54) *(1/100)*(1 km/1000)

72. HSTMr. Watson Example How many kilometers are there in 0.200 miles? solve mathematics #km = (0.200)*(5280)*(12)*(2.54) *(1/100)*(1 km/1000) = 0.322 km 3 sig. fig.

73. HSTMr. Watson Example How many kilometers are there in 0.200 miles? solve mathematics #km = (0.200)*(5280)*(12)*(2.54) *(1/100)*(1 km/1000) = 0.322 km 3 sig. fig.exact numbers