1. Dimensional analysis and Units of Measurements

2. Dimensional analysis Dimensional analysis uses conversion factors to convert from one unit to another. Also called Factor Label (and railroad tracks) You do this in your head all the time – How many quarters are in 4 dollars?

3. Dimensional analysis practice 3 Big Mac = 7 salads 9 salads = 2 slices of pepperoni pizza 22 slices of pepperoni pizza = 27 Sonic cokes Ex. 1) What number of Big Macs equal 365.4 salads? Ex. 2) How many sonic cokes do you have to drink to equal 11 salads?

4. Units of Measurement Meter m Liter L Celsius C

5. Mass is the amount of matter, weight is a measure of the gravitational pull on matter

6. SI Units PrefixSymbolScientific notationFactorExample MegaM1 x 10 6 1,000,000megagram (Mg) Kilok1 x 10 3 1,000kilometer (km) Hectoh1 x 10 2 100hectoliter (hL) Dekada or (D)1 x 10 1 10dekagram (Dg) BASE UNIT1 x 10 0 1meter Decid1 x 10 -1.1deciliter (dL) Centic1 x 10 -2.01centimeter (cm) Millim1 x 10 -3.001milligram (mg) Microu1 x 10 -6.000001microgram (ug) Nanon1 x 10 -9.000000001nanometer (nm) Picop1 x 10 -12.000000000001picogram (pg)

7. Practice In each pair below, circle the larger MillimeterCentimeter picometerMicrometer kilogramHectogram decilitermillileter

8. Practice In each pair below, circle the larger MillimeterCentimeter picometerMicrometer kilogramHectogram decilitermillileter

9. Practice In each pair below, circle the larger MillimeterCentimeter picometerMicrometer kilogramHectogram decilitermillileter

10. Practice In each pair below, circle the larger MillimeterCentimeter picometerMicrometer kilogramHectogram decilitermillileter

11. Practice In each pair below, circle the larger MillimeterCentimeter picometerMicrometer kilogramHectogram decilitermillileter

12. Basic SI Units QuantityBase unit Lengthmeter (m) Massgram (g) Timesecond (s) VolumeLiter (L) TemperatureKelvin (K) or Celsius (C) Amount of substancemole (mol) Heat & Energyjoule (J)

13. Metric Conversions Practice Ex. 3) 2.435 g __________________cg Ex. 4) 23.8 mL = ________________kL Ex. 5) 23.5 cs = ________________ns

14. Some Useful Conversions Length: 1 in = 2.54 cm 1 mi = 5280 ft Volume: 1 cm 3 = 1 mL 1 L = 1.06 qt Weight: 1 kg = 2.2 lb 16 oz = 1 lb 1 ton = 2000 lb

16. Temperature 20°C = K Use both the Kelvin and Celsius scale, to convert Celsius + 273 = Kelvin Kelvin -273 = Celsius

17. Temperature 20°C = 293 K Use both the Kelvin and Celsius scale, to convert Celsius + 273 = Kelvin Kelvin -273 = Celsius

18. Temperature 20°C = 293 K 373 K = °C Use both the Kelvin and Celsius scale, to convert Celsius + 273 = Kelvin Kelvin -273 = Celsius

19. Temperature 20°C = 293 K 373 K = 100 °C Use both the Kelvin and Celsius scale, to convert Celsius + 273 = Kelvin Kelvin -273 = Celsius

20. Volume: measured in cubic centimeters (cm 3 ) or liters 1 liter (L) = 1 cubic decimeter (dm 3 ) = 1000 millileters (mL) 1 mL= 1 cm 3

21. Volume can be measure by Length x x or the Water Displacement method

22. Volume can be measure by Length x width x or the Water Displacement method

23. Volume can be measure by Length x width x height or the Water Displacement method

24. Volume can be measure by Length x width x height or the Water Displacement method Know the relationship between the following volume units… L = mL = cm 3 (or cc in medical lingo)

25. Volume can be measure by Length x width x height or the Water Displacement method Know the relationship between the following volume units… 1 L = mL = cm 3 (or cc in medical lingo)

26. Volume can be measure by Length x width x height or the Water Displacement method Know the relationship between the following volume units… 1 L = 1000 mL = cm 3 (or cc in medical lingo)

27. Volume can be measure by Length x width x height or the Water Displacement method Know the relationship between the following volume units… 1 L = 1000 mL = 1000 cm 3 (or cc in medical lingo)

28. Density Is the ratio of mass per unit of volume. How much matter is packed into a given amount of space Density = mass/volume D= m/v

29. The Density of a substance stays regardless of the size of the sample. For example: if you cut a block of copper in half, you have decreased both the mass and volume, the ratio of the 2 stays the same. This is called an Intensive Physical Property.

30. The Density of a substance stays constant regardless of the size of the sample. For example: if you cut a block of copper in half, you have decreased both the mass and volume, the ratio of the 2 stays the same. This is called an Intensive Physical Property.

31. The appropriate units of density are: for solids for liquids

32. The appropriate units of density are: g/cm 3 for solids for liquids

33. The appropriate units of density are: g/cm 3 for solids g/mL for liquids

34. Example problems: A sample of aluminum metal has a mass of 8.4g. The volume of the sample is 3.1 cm 3. Calculate the Density of aluminum.

35. Example problems: A sample of aluminum metal has a mass of 8.4g. The volume of the sample is 3.1 cm 3. Calculate the Density of aluminum. 8.4 g/3.1 cm 3 =

36. Example problems: A sample of aluminum metal has a mass of 8.4 g. The volume of the sample is 3.1 cm 3. Calculate the Density of aluminum. 8.4 g/3.1 cm 3 = 2.7 g/cm 3

37. Example problems: Diamond has a density of 3.26 g/cm 3. What is the mass of a diamond that has a volume of 0.350 cm 3 ?

38. Example problems: Diamond has a density of 3.26 g/cm 3. What is the mass of a diamond that has a volume of 0.350 cm 3 ? 3.26 g/cm 3 x 0.350 cm 3 =

39. Example problems: Diamond has a density of 3.26 g/cm 3. What is the mass of a diamond that has a volume of 0.350 cm 3 ? 3.26 g/cm 3 x 0.350 cm 3 = 1.14 g

40. Example problems: What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/mL?

41. Example problems: What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/mL? 76.2 g = 13.6 g/mL

42. Example problems: What is the volume of a sample of liquid mercury that has a mass of 76.2 g, given that the density of mercury is 13.6 g/mL? 76.2 g = 5.60 mL 13.6 g/mL

43. Reliable Measurements refers to the closeness of the measure value is to the, or real, value. refers to how a series of measurements are to one another.

44. Reliable Measurements Accuracy refers to the closeness of the measure value is to the, or real, value. refers to how a series of measurements are to one another.

45. Reliable Measurements Accuracy refers to the closeness of the measure value is to the accepted, or real, value. refers to how a series of measurements are to one another.

46. Reliable Measurements Accuracy refers to the closeness of the measure value is to the accepted, or real, value. Precision refers to how a series of measurements are to one another.

47. Reliable Measurements Accuracy refers to the closeness of the measure value is to the accepted, or real, value. Precision refers to how close a series of measurements are to one another.

49. is calculated by subtracting the value from the value.

50. Error is calculated by subtracting the experimental value from the accepted value.

51. The is the ratio of an error to an accepted value.

52. The percent error is the ratio of an error to an accepted value.

53. % error = error x 100 = accepted value – experimental value x 100 accepted value accepted value

54. Example An experiment finds the density of lead to be 10.95 g/cm 3. The literature value for the density of lead is 13.34 g/cm 3.

55. The error: accepted value – experimental value= 13.34 – 10.95 = An experiment finds the density of lead to be 10.95 g/cm 3. The literature value for the density of lead is 13.34 g/cm 3.

56. The error: accepted value – experimental value= 13.34 – 10.95 = 2.39 An experiment finds the density of lead to be 10.95 g/cm 3. The literature value for the density of lead is 13.34 g/cm 3.

57. The error: accepted value – experimental value= 13.34 – 10.95 = 2.39 The % error: error x 100 = accepted value 2.39 x 100 = 13.34

58. The error: accepted value – experimental value= 13.34 – 10.95 = 2.39 The % error: error x 100 = accepted value 2.39 x 100 = 17.9% 13.34

59. Practice Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0?

60. Practice Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0? 28.9 – 27.0 =

61. Practice Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0? 28.9 – 27.0 = 1.90

62. Practice Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0? 28.9 – 27.0 = 1.90 1.90/27.0 x 100% =

63. Practice Sara’s lab shows the atomic mass of aluminum to be 28.9. What is her percent error if the accepted value is 27.0? 28.9 – 27.0 = 1.90 1.90/27.0 x 100% = 7.04%

64. Practice What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C?

65. Practice What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C? 60.8 °C – 40.6 °C =

66. Practice What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C? 60.8 °C – 40.6 °C = 20.2 °C

67. Practice What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C? 60.8 °C – 40.6 °C = 20.2 °C 20.2 °C / 60.8 °C x 100% =

68. Practice What is the percent error in a measurement of the boiling point of bromine if the textbook value is 60.8 °C and the lab value is 40.6 °C? 60.8 °C – 40.6 °C = 20.2 °C 20.2 °C / 60.8 °C x 100% = 33.2%