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Chapter 1

Chapter 1. The Nature of Chemistry. Section 1.1 - What is Chemistry?. Is the study of the composition of matter and the changes they undergo. Matter Anything that takes up space and has mass. Two types of chemical careers:.

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Chapter 1

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  1. Chapter 1 The Nature of Chemistry

  2. Section 1.1 - What is Chemistry? • Is the study of the composition of matter and the changes they undergo. • Matter • Anything that takes up space and has mass.

  3. Two types of chemical careers: • Applied Chemistry- use the knowledge of chemistry in their profession. • Nuclear Submarine engineer, Teacher, Pharmacist, etc. • Pure Chemistry- use the knowledge to discover new information on chemistry. • Scientist studying the depletion of ozone, or any scientific unknowns.

  4. Section 1.1 • Chemistry is the Central Science. • It overlaps many other sciences, do to the fact that everything is made up of chemicals.

  5. Section 1.1 • Five major branches of chemistry: • Organic chemistry • Living or once living material, contain Carbon and Hydrogen. • Inorganic chemistry • Nonliving material, metals, plastic, minerals, etc. • Analytical chemistry • Qualitative and Quantitative study of matter. • Physical chemistry • Energies within the atoms and subatomic particles. • Biochemistry • Chemistry within living organisms.

  6. Section 1.1 • Determine which branch of Chemistry is most appropriate to the study: • Study of the respiration in fish. • Amount of mercury levels within fish at in the Allegheny river. • Process of converting crude oil into motor oil. • Determining the energy of a single electron. • Improving the hardness of steel.

  7. Section 1.2 • Steps of the Scientific Method • Observation • Hypothesize • Experiment • Conclude (Theory) • Natural Law – helps to describe how nature behaves but does not explain why nature behaves in that particular way. • Theory – statement explaining how things occur in relationship to the natural law. Can still be proven wrong. “superhypothesis”

  8. Section 1.3 Safety in Laboratory • Follow teacher’s directions. • Notify teacher of problems. • Know how to use the safety equipment. • Emergency eyewash and shower. • Wear safety goggles. • Tie back long hair and loose clothing. • If it’s hot, let it cool. • Carry chemicals with caution. • Dispose of chemical waste properly. • Clean Up!!!

  9. 1.3 Symbols. Safety gloves Safety clothing Safety goggles Heating Poison Corrosive Fumes Fire Electrical Outlet Explosive Wash hands Radioactive Waste Disposal

  10. Section 1.6Working with Numbers • Scientific Notation or Exponential Notation • n. x 10e • Where n is a digit 1-9. e is the exponent.

  11. Section 1.6Working with Numbers • Converting to scientific notation • Must move the decimal to the ONES position. • Number of spaces needed is the exponent. • Moving the decimal left, is a positive exponent. • Moving the decimal right, is a negative exponent.

  12. Section 1.6Working with Numbers • Convert the following to scientific notation. • 2300. cm .00522 kg 1.432m

  13. Section 1.6Working with Numbers • Converting to standard notation. • Positive exponent, move the decimal to the right the number of places as the exponent. • Negative exponent, move the decimal to the left the number of places as the exponent.

  14. Section 1.6Working with Numbers • Convert the following to standard notation. • 4.55 x 103 m 1.24 x 10-4 kg

  15. Section 1.4Units of Measurement • Metric System • The International System of Units Standard • Based upon tens or decimal places. • Used throughout the world.

  16. Section 1.4Units of Measurement • International System of Units (S.I.) • Le Systeme International d`Unites.

  17. Section 1.4Units of Measurement Standard S.I. Units • Length – meter (m) • Mass – kilogram (kg) • Derived Units: • Area – length x width = (m2) • Volume – length x width x height = (m3) • Liquid Volume – (mL)

  18. Section 1.4Units of Measurement • Other common S.I. Units used in chemistry. • Pressure – pascals (Pa) • Temperature – kelvins (K)

  19. Section 1.4Units of Measurement • Converting metric units using prefixes • Prefix and Value • Large Prefixes: • Tera (T) = 1012 • Giga (G) = 109 • Mega (M) = 106 • Kilo (k) = 103 • Hecto (h) = 102 • Deca (da) = 101 • Base – no prefix (m, g, L, Hz or K ….) • Small Prefixes: • deci (d) = 10-1 • centi (c) = 10-2 • milli (m) = 10-3 • micro (μ) = 10-6 • nano (n) = 10-9 • pico (p) = 10-12

  20. Section 1.5Uncertainty in Measurement • Precision – Repeatable measurement. • Accuracy – Closeness to the correct value. • Describe the following lists of measure by accurate or precise: (+/- .5 error) • 4.55g , 4.60g , 4.58g ; The true value is 4.60g • 1.2m , 2.0m , 2.5 m ; The true value is 1.0m

  21. Section 1.6Working with Numbers • Significant Digits • The certain digits and the estimated digits are together called the significant digits.

  22. Rules for significant digits: • All non-zero digits are significant. • 1234 5663 121112 • Zeroes in between two non-zero digits are always significant. • 103 1004 102003 • Zeroes after a non-zero digits are only significant if the number has a decimal. • 200. 3450. 10. • Zeroes after non-zero digits are not significant if the number has no decimal. • 200 40020 4230 • Zeroes in front of non-zero digits are never significant. • .00004 0.0343 .00430

  23. Section 1.6Working with Numbers • Significant Digits in Calculations • Round all answers to the fewest significant digits that is shown in the given. • Standard rule is to round all to 3 sig figs. • Scientific Notation is the easiest way of writing the correct number of significant digits. • Every number in scientific notation before the (x10e) will always be a significant digit. • Example • 4000 g has 1 significant digit • 4.00 x 103 g has 3 significant digits.

  24. Section 1.6Working with Numbers • Practice, answer the following problems and round to 3 significant figures: • 303 cm + 900 cm + 23 cm = • 4.5 x 105 g + 1.2 x 103 g = • 60.7 cm  205 cm  4 cm = • 22.2 g / 75 cm3 =

  25. Using dimensional analysis with prefixes. • Dimensional Analysis • Technique of converting units and solving problems. • Uses Conversion Factors: • Units of equality. • Set prefix value equal to unit of the base value. • Ex. mm to m: 1 mm = 1x10-3m • Always start with the known value and express it as a fraction over 1. • Setup the conversion so that the unit of the known cancels out the unit in the conversion.

  26. Section 1.4Units of Measurement • Convert 30 cm to m. • Convert 50 kg to g.

  27. Section 1.4Units of Measurement • Convert 4 m to cm. • Convert 400 g to kg.

  28. Section 1.4Units of Measurement • Multiple prefix conversions use two conversion factors. • Example: Converting 400 cm to km. • 400 cm = ____ km • c = 10 -2 and k = 10 3 • 1x10-2m = 1cm and 1x103km = 1m • 4 x 10 -3 km

  29. Section 1.4 • Practice • 8.2 x 10-23 cm = ? nm • 1.3 x 10-2 mm = ? km • 5.2 x 10 8 pm = ? m • 2.6 x 10 19 Mm = ? mm

  30. Conversion of Cubic Units of Volume • Ideal method of converting cubic or squared units, is by using the basic units. • 1 cm 3 = 1 mL • 1 m3 = 1000 L • 1 x 106 cm3 = 1 m3 , How? • Note the basic metric equality between the units: • 100 cm = 1 m or (1 x 102 cm = 1 m) • Cube both sides, (1x102 cm)3 =(1m)3

  31. Conversion of Cubic Units of Volume • 350 mm3 = ? cm3 • 1 mm = 1x10-3 m • Cube both units and values. • 1 mm3 = 1x10-9 m3 and • 1cm = 1x10-2m • Cubed : 1cm3 = 1x10-6m3

  32. Conversion of Cubic Units of Volume • Practice • 1.2 x 10-3 nm3 = ? mL • 1.4 x 10-2 m3 = ? mm3

  33. Section 1.5Uncertainty in Measurement • Recording a Measurement • All known digits of a measurement and an estimated digit should always be recorded. • Example: Using a graduated cylinder, you can record known digits to the ones and estimate the tenths.

  34. Section 1.7Problem Solving • Dimensional Analysis • Technique of converting units and solving problems. • Uses Conversion Factors: • Units of equality. • 1ft = 12in • Always start with the known value and express it as a fraction over 1. • Setup the conversion so that the unit of the known cancels out the unit in the conversion.

  35. Section 1.7Problem Solving • Example Problem: • How many feet are in 400. inches? • Conversion 1 ft = 12 in • Known 400 in

  36. Section 1.7Problem Solving • Multiple step problem. • How many cm are in 2 miles?

  37. Section 1.7Problem Solving • Complex Problems • How many mi/hr are equivalent to 60 ft/s?

  38. Section 1.7Problem Solving • Four-Step Problem-Solving Strategy • Analyze • Plan • Solve • Evaluate

  39. Section 1.7Problem Solving • Determine the number of seconds in 2009 years. Not counting leap years.

  40. p.p#37 • If 1500 white blood cells (WBC) are lined up side by side they would form a row 1.0 in long. What is the average diameter in micrometers of a single WBC? (1in = 2.54cm)

  41. p.p. #38 • A radio wave travels 186000 miles per second. How many kilometers will the wave travel in one microsecond? (1 mi = 1.61 km)

  42. p.p. #40 • Eggs are shipped from a poultry farm in trucks. The eggs are packed in cartons of one dozen eggs each; the cartons are placed in crates that hold 20 cartons each. The crates are stacked in the trucks, 5 crates across, 25 crates deep, and 25 crates high. How many eggs are in 5 truckloads?

  43. p.p. #41 • Iodine is an essential nutrient in our diet that prevents goiter. To obtain enough iodine, we can use iodized salt, which is .01%NaI by mass. How many kilograms of NaI should be added to 1000kg of table salt to achieve this percentage of NaI?

  44. p.p. #42 • The antlers of a deer are 50% Ca by mass. The calcium comes from leaves that the deer eat. The leaves are .07%Ca by mass. How many kilograms of leaves would a deer need to eat in order to provide enough calcium to grow antlers weighing 3 kilograms?

  45. Section 1.6Working with Numbers • Percent Error • A percent value, showing the amount error in an experiment.

  46. Example: • Allison and Todd had completed an experiment together and found the density of water to be .839 g/mL. Knowing the true density of water to be 1g/mL, what was their percent error?

  47. Section 1.6Working with Numbers • Conversions or Ratios • Equalities expressed as fractions. • Speed = distance / time • Density = mass / volume • Knowing the density of water = 1 g/cm3 • What is the mass of 200 cm3 of water? • What is the volume of 34g of water?

  48. Section 1.6Density • What is the mass of 200 cm3 of water? • Knowing the density of water is 1g/cm3 • Answer : • What is the volume of 34 g of water? • Answer :

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