Conservation

1
Conservation

• 2C

2
Objectives

• The Student Will Be Able To
• 1. demonstrate an understanding of the Law of
  Conservation of Matter, given experimental
  data(2.2)
• 2. Identify the types of chemical
  reactions(Synthesis, Decomposition, Single and
  Double Replacement) and balance the
  equation.(6.3, 6.4)
• 3. If given, at the very least, the reactants, be
  able to predict the products of a reaction in
  aqueous solution and balance the equation(6.3,
  6.4)
• 4. Learn the natural states of common
  elements(4.9)

3
Introduction

• 1. What is the difference between science and
  technology?
• Science is the process of gathering, analyzing,
  and organizing knowledge about the natural world
• Technology is the application of science
  converting natural resources into goods and
  services

4
Introduction

• 2. How often does scientific knowledge double?
• every nine to 10 years
• 3. How much of the earths population does the
  US represent?
• 5

5
Introduction

• 4. About how much of the earths resources do we
  use?
• about half
• 5. How much resources does a typical US citizen
  consume in his or her lifetime?
• 52 tons of iron and steel, 6.5 tons of paper,
  1200 barrels of oil, 21,000 gallons of gasoline,
  50 tons of food, 5 tons of fertilizer, and more

6
Introduction

• 6. About how much garbage will a typical US
  citizen discard?
• 126 tons

7
Using things up

• 7. When we use up erasers on our pencils, or
  gasoline in our cars, are they disappearing?
• no, the atoms are rearranging themselves to form
  new things that may or may not be usable.
• 8. What does it mean to use something up?
• changing resources-sometimes they can be
  reclaimed sometimes they cannot

8
Keeping Track of Atoms

• 9. What is the chemical equation that describes
  the burning of coal?
• C(s) O2(g) --gt CO2(g)
• 10. Does this equation account for all atoms on
  either side?
• Yes, you have 1 carbon on left and right and 2
  Os on left and right

9
Keeping Track of Atoms

• 11. What is the chemical equation that describes
  the rusting of copper?
• Cu(s) O2(g) --gt Cu2O
• 12. Does this equation account for all atoms on
  either side?
• No, you have 1 Cu on left and 2 on right you
  have 2 O on left and 1 on right

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Keeping Track of Atoms

• 13. What Law of Conservation of Matter states?
  Who proposed it?
• all the atoms that you begin with in a chemical
  reaction you have to end up with. Antoine
  Lavoisier matter cannot be created or
  destroyed, it can only change forms
• 14. Does this last equation obey this law?
• No

11
Keeping Track of Atoms

• 15. How do we fix the equation so as to make it
  conform to the law?
• you add coefficients(big numbers) to the
  beginning of each type of molecule until
  everything equals out
• 16. What do we call this equation now?
• a balanced equation

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• 17. What are some simple rules that can help us
  balance equations
• 1. Move from left to right
• 2. Try to make any odd numbered elements even by
  adding a two as a coefficient
• 3. make water HOH
• 4. keep polyatomic ions as a unit, dont split
  them up
• 5. Always double check your work!
• 6. Above all else check to make sure your
  chemical formulas are correct

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• 18. Write Balanced Chemical Equations for the
  following
• a. Sodium chloride and Barium sulfate yields
  sodium sulfate and barium chloride
• b. Hydrochloric acid and sodium hydroxide yields
  dihydrogen monoxide and sodium chloride

14

• Potassium chromate and Silver nitrate yields
  potassium nitrate and silver chromate
• d. Aluminum nitrite and Barium phosphate yields
  Aluminum phosphate and Barium nitrite

15
Keeping Track of Atoms

• 19. What other pieces of information can be used
  with a balanced equation?
• its phase
• 20. What are the 4 phases that molecules can
  find themselves in and what are their symbols?
• solid - s liquid- l gas -g
  aqueous(dissolved in water)- aq

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• 21. How do you know if something is aq or not?
• Ask yourself two questions
• Is the reaction taking place in water(usually
  they will use the word solution to say that)?
• Will the compound dissolve in water(look on your
  solubility chart)
• s means soluble-it will dissolve! put down aq
• Any other other symbol means it will not--put
  down s for solid

17
Keeping Track of Atoms

• 22. You drop crystals from the following ionic
  compounds. Will they dissolve in water? Write
  down (s) if they do not, (aq)
• a. Silver chloride
• b. Sodium nitrate
• c. Iron III phosphate
• d. Copper II chloride

18
Keeping Track of Atoms

• 22. Write correctly balanced equations including
  their phases
• a. Solutions of Sodium hydroxide and Iron III
  nitrate yields Sodium nitrate and Iron III
  hydroxide
• b. Solutions of Barium nitrate and Potassium
  sulfate yields Barium sulfate and Potassium
  nitrate

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• c. Solutions of Copper II chloride and Lead II
  nitrate yields Lead II chloride and Copper II
  nitrate
• d. Al and and a solution of Copper II chloride
  yields Copper metal and Aluminum chloride

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• 23. Examples a-c on 22 are examples of Double
  Replacement, while example d is an example of a
  single replacement reaction. Why do you think
  they are called those things?
• 24. What is an analogy for remembering Single
  Replacement Reactions? What is the general
  equation?
• Dancingsomeone cutting in, breaking up the pair
  A BC --gt B AC

21
Keeping Track of Atoms

• 25. What is an analogy for remembering Double
  Replacement Reactions? What is its general
  formula?
• Swingingswitching partners AB CD --gt AD
  CB

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• 26. Determine whether the following are examples
  of Double or Single Replacement Reactions and
  balance them with correct phase notation
• a. Magnesium metal is mixed with silver nitrate
  solution to produce Magnesium nitrate solution
  and Silver metal
• b. Potassium hydroxide solution is mixed with
  Iron III chloride to produce Potassium chloride
  and Iron III hydroxide

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• c. Solution of Barium chloride is mixed with a
  solution of Mercury II nitrate to produce Mercury
  II chloride and Barium nitrate
• d. Copper metal is submerged in a solution of
  Magnesium nitrate to produce Magnesium metal and
  Copper II nitrate

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• 27. Knowing the General Equations, we can even
  predict what will happen if all we are given are
  the reactants. If nothing becomes solid (s) then
  we say that the reaction does not occur. The key
  things that you need are the Solubility Chart for
  DR reactions and the Activity Series for the SR
  reactions. Write correctly balanced equations
  including phase notation
• a. Solutions of Silver nitrate and Magnesium
  metal are mixed

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• b. Solution of Lead II nitrate is mixed with a
  solution of sodium chloride
• c. Solution of Magnesium nitrate is mixed with
  Zinc metal
• d. Sodium chloride solution is mixed with Barium
  nitrate solution

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• There are two other major types of reactions.
  What are they? What analogy can we use to
  describe them and what are their General
  Equation?
• Synthesis Marriage A B --gt AB
• Decomposition Divorce AB --gt A B

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• 29. There are 7 elements on the earth that
  always comes in twos, a couple...these are called
  the Diatomic Molecules. What are they? What
  acronym can you use to remember them?
• Br2, H2, O2, N2, Cl2, I2, F2 Br. HONClIF or
  Brave Clowns Never Have Offered Free Ice or
  Hydrogen plus 7

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• 30. Determine whether the following are examples
  of DR, SR, S, D. Balance and place correct phase
  notation.
• a. Hydrogen gas and Oxygen gas react to form
  water
• b. Hydrogen peroxide liquid breaks down into
  Oxygen gas and water

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• c. Potassium dichromate solution and Iron III
  chloride solution mix...
• d. Barium metal reacts with water...

30
Resources and Waste

• 31. To satisfy the needs of the average
  American, how much resources must be withdrawn
  form the Earth each year?
• 23,000 kg(25 tons)
• 32. What is a bad side effect of obtaining and
  using these resources?
• changes the materials into other ones that may
  not be wanted

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• 33. What are two examples of this concept?
• burning coal generates corrosive gases that enter
  the atmosphere to form Very Acidic Rain
• Extracting a metal from an ore leaves behind
  solid by products which must be discarded
• 34. What is another way in which we produce
  waste?
• we use up consumer products(Al in chewing gum,
  plastic wrappers, styrofoam cups.)

32
Resources and Waste

• 35. What is a discard?
• something we no longer use
• 36. How much does the average American throw
  away each day?
• 2 kg(4 lbs) half of it is paper

33
Resources and Waste

• 37. What is a good analogy for understanding how
  much trash we as Americans discard each day?
• filling the New Orleans Superdome from top to
  bottom 2 x each day
• 38. What is pollution?
• unwanted, sometimes harmful materials, discarded
  carelessly

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Resources and Waste

• 39. Why do we say that that some pollutants are
  resources out of place?
• many of the glass and metallic trash items can be
  reprocessed so that they can be used again.
• 40. What does it mean to be recycled?
• reprocessing materials in manufactured items to
  make new manufactured items

36
Resources and Waste

• 41. What do you do with discards generated by
  your daily activities?
• Disposing of Things we no Longer Need
• 42. Look at the following Figure.

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Disposing of Things we no Longer Need

• What has happened to the net discards in the past
  20 years? What about energy use? What about
  materials recovered?
• stayed the same gone up gone up

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Disposing of Things we no Longer Need

• 43. Look at the Table.

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41
Disposing of Things we no Longer Need

• What is the number one most discarded material?
  Which two big discards have gone down by in the
  last 16 years?
• paper glass, metals
• 44. What is the difference between renewable and
  nonrenewable resources?
• renewable-nature can replenish--paper and wood
• non renewable-nature cannot replenish
  anymore--metals, coal, petroleum

42
Disposing of Things we no Longer Need

• 45. What resources make up your pencil?
• 46. What are renewable and what are non
  renewable?

43
Counting and Weighing Atoms, Molecules, and Ions

• Look at this balanced equation
• Cu2S (s) 2O2 (g) --gt 2CuO SO2 (g)
• 47. How can we interpret this in formation?
• 1 Formula unit (FU) of Cu2S reacts with 2
  molecules of O2 to form 2 FU of CuO and 1
  molecule of SO2.

44
Counting and Weighing Atoms, Molecules, and Ions

• Cu2S (s) 2O2 (g) --gt 2CuO SO2 (g)
• 48. What is the difference between FU and
  molecule?
• FU is the smallest particle of an ionic compound
  (M NM)
• Molecule is the smallest particle of a molecule
  (NM NM)

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Counting and Weighing Atoms, Molecules, and Ions

• 49. Is this equation very practical if you are a
  Copper refinery owner who wants to know how much
  SO2 air pollutant will be released by roasting
  Cu2S?
• No, he needs to know amounts in terms of a
  practical unit like L or g.
• 50. What unit has been created to help solve this
  problem?
• The Mole

46
Counting and Weighing Atoms, Molecules, and Ions

• 51. What is a mole like?
• Small and furry. Oh, it stands for a particular
  number of things like a dozen is 12, gross is
  144, and a ream is 500.
• 14. How many things is a mole?
• 6.02 x 10 23

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Counting and Weighing Atoms, Molecules, and Ions

• 52. How big is this number?
• If you were to string a mole of paperclips around
  the earth it would circle the earth 50 trillion
  times.
• 53. How big is a mole of water?
• 1/10 of a cup, a mouthful, 18mL

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Counting and Weighing Atoms, Molecules, and Ions

• 54. Why is the mole so useful in Chemistry?
• Atoms, FUs, and molecules are so small that only
  when you are dealing with mole amounts can you be
  dealing with handy amounts.
• 55. What is the relationship between the atoms
  atomic mass and the mole?
• One mole of any atom is equal to its atomic mass
  in grams.

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One mole of stuff
50
Counting and Weighing Atoms, Molecules, and Ions

• 56. What is the mass of one mole of the
  following?
• Add the atomic masses of the atom in the
  following equations
• S, Cu, Cu2S, O2, SO2, CuO
• 57. What are these mass called?
• Their Molar Mass.

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• 58. So how can we interpret the original equation
  now?
• Cu2S 2O2 --gt 2CuO SO2
• 1 mole 2 mole --gt 2 mole 1 mole
• 159.2g. 64.0g. --gt 159.2g. 64.0g.
• 59. Why do we say that the above equation obeys
  the Law of Conservation of Matter?
• Because the mass of the reactants equal the mass
  of the products

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• 60. Where do most chemical reactions take place
  in?
• Water solutions
• 61. What is molarity?
• The number of moles of solute dissolved in L of
  solution (solute solvent).

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• 62. What is its symbol?
• M
• 63. How would you make a 1M solution of Sugar?

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• 64. How would you make a .50 M solution of NaCl?
• 65. How would you make a 2M solution of
  Hydrochloric Acid?

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• 66. How would you make a 200mL of a 3M solution
  of Sodium Hydroxide?
• 67. How would you make a 150mL of a .5M solution
  of Copper II Nitrate?
• 68. How would you make a 300mL of a 2.5M solution
  of Barium nitrate?

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Conservation Must be Our Way

• 69. In what two ways are we depleting our
  resources?
• 1. Nature conserves atoms not molecules. Some of
  the molecules we use are produced very slowly.
• 2. We are using up ores that have a high
  concentration of the metals. Soon all we will
  have left are ores with low concentrations of the
  metal.

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• 70. When we say that we have an ore that has a
  high concentration of Copper, we say that its
  percentage composition is high. What is
  percentage composition?
• The fraction of a particular element in a
  compound

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• 71. How do you determine composition?
• 1. Find the molar mass
• 2. Divide the molar mass into the total mass of
  each
• element
• 3. Multiply by 100

59

• 72. Find the composition for the following
• NaOH
• b. HCl
• c. Cu(NO3)2
• d. K2CO3

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• 73. Which of the following two minerals contain
  the highest percentage by mass of Cu?
• CuFeS2
• b. Cu2CO3(OH)2
• c. Cu3(CO3)2(OH)2

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Lab Retrieving Copper
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• 74. Nature may be in charge of conserving at the
  atom level, but how can we slow down the rate at
  which we deplete the molecules we use?
• The three Rs Replace, Reuse, and Recycle
• 75. Give two examples of each

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• 76. Why are we called a throwaway society?
• 30 of the US production is discarded. It takes
  10 of all our energy to handle the discarded
  materials.
• 77. Some of our critics accuse us of
  overpackaging. Give examples of this

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• 78. What are some ways that we can reduce
• overpackaging?
• Use less, buy in bulk, use items for a longer
  time, repair instead of discard.
• Recycling requires considerable work but it also
  has lots of benefits. Lets look at the details
  of the recycling of Paper, Aluminum, and Glass.

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• 79. How long does it take a seedling for it to
  grow large enough to cut down for paper?
• 25 years.
• 80. How many trees gives us a ton of paper?
• 17 trees 1 ton enough paper for two people
  for a year
• 81. How much less energy is required to reprocess
  paper?
• Less than half

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• 82. About how much of paper is correctly being
  recycled?
• About 30
• 83. What is the most abundant metal on the
  earths crust?
• Al 8
• 84. Thats good news, what is the bad news?
• Most of it is difficult to get out of mineral
  form
• 85. What is the name of the most plentiful Al
  ore?
• Bauxite

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• 86. How much of the bauxite do we import?
• 85
• 87. How much less energy is used when we recycle?
• 1/20th
• 88. How much of the Al are we now recycling?
• About 50

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• 89. How is glass made?
• By melting sand, SiO2, soda ash(Na2CO3), and
  limestone(CaCO3) together at high temp
• 90. Why is it easier to reuse glass bottles than
  to make new ones?
• Because it requires so much energy to melt it

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You Decide

• 91. Which of the three materials described above
  is the most important to recycle for economic
  reasons? For political reasons? For
  environmental reasons? Explain your answers.
• 92. If recycling is important, should the federal
  government require that certain materials be
  recycled? If so, identify some materials that
  should be recycled under such a law. How could
  such a law be enforced?

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• 93. As individuals, we can conserve, reuse, or
  recycle materials in many different ways. For
  example, we can use both sides of paper for
  writing, or, when gives a choice, purchase
  beverages in returnable bottles and return them.
  Identify at least five ways we, as individuals,
  can conserve, reuse, or recycle certain
  materials.

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• 94. Describe three everyday routines you would be
  willing to change to reduce the problems of solid
  waste disposal.
• 95. We plant forests to supply our paper needs.
  Assume that all printed or typewritten
  communication is replaced in the future by
  computer based networks. What current uses of
  paper would cease? What occupation or jobs would
  be eliminated? What would you be reading in
  place of this paper worksheet? How else would
  your daily routine be changed by this
  technological advancement?

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Do Building Skills 10
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Do Making Decisions on p 149