Bell work

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Bell work
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Chemical Reactions
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• Modern Chemistry Chapter 8.1 pg. 261-274
• 3221.3.7 Balance an equation for a chemical
  reaction.

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Chemical Reactions

• there are gobs of chemical reactions that are
  taking place all around us right now, many of
  these chemical reactions add to the many
  conveniences of life that you enjoy today!

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Chemical Reactions

• Describe one particular reaction that is
  important to many Americans during the winter
  months?
• Methane gas and oxygen gas form carbon dioxide
  and water

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Chemical Reactions

• Q2 What is the another way of describing the
  previous reaction?
• CH4(g) O2 (g) --gt CO2 (g) H2O(l)

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Chemical Reactions

• Q3 What advantages do we have in describing
  equations this way?
• shorter
• easier to read
• faster
• Internationally recognized

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Chemical Reactions

• All equations have several things in common
• reactants chemicals that react!
• products chemicals that are produced
• --gt yields or produces

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Chemical Reactions

• What does the Law of Conservation of Matter
  state? Who stated it?
• Matter cannot be created or destroyed but will
  rearrange itself-Lavoiser

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Chemical Reactions

• when you do not have equal numbers of atoms of
  the same element on either side of an equation,
  the equation is said to be unbalanced.
• In order to write a correct chemical equation
  the Law must be applied and you must have a
  balanced chemical equation

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Chemical Reactions

• you balance a chemical equation by adding
  coefficients in front of the chemical formulas
• a coefficient is a big number that tells us how
  many of the things( it precedes) we have in the
  equation

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• Q6 Name some simple rules for balancing
  equations
• 1. Move from left to right
• 2. Try to make any odd numbered elements even by
  adding a two as a coefficient
• 3. Do H and O last
• 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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Chemical Reactions

• Ex. 1 Balance the equation that we have been
  looking at?
• CH4(g) 2 O2 (g) --gt CO2 (g) 2HOH(l)

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• Ex. 2 Write a balanced equation for the rxn
  between chlorine gas and sodium bromide to
  produce bromine liquid and sodium chloride?
• 2NaBr Cl2 --gt Br2 2NaCl

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Chemical Reactions

• Ex. 3 Write the balanced equation for the rxn
  between aluminum sulfate and calcium chloride to
  produce aluminum chloride and calcium sulfate?
• Al2 (SO4) 3 3CaCl2 -- gt 2 AlCl3 3 CaSO4

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Practice

• a. Sodium and oxygen gas combining to form
  sodium oxide
• 4Na O2 --gt 2Na2O
• b. Copper and sulfur combining to form Copper
  II sulfide
• Cu S --gt CuS

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Practice

• c. Copper I oxide combining with hydrogen gas
  to form Copper and Water
• Cu2O H2 --gt 2 Cu HOH
• d. Barium hydroxide reacting with carbon
  dioxide to form barium carbonate and water
• Ba(OH) 2 CO2 --gt BaCO3 HOH

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• e. Iron III oxide is produced when Iron reacts
  with oxygen
• 4Fe 3O2 --gt 2Fe2O3
• f. Sodium hydroxide and hydrogen gas are
  formed when sodium reacts with water
• 2Na 2HOH --gt H2 2NaOH
• g. Copper and sulfuric acid will react to
  produce Copper II sulfate, water and sulfur
  dioxide
• Cu 2H2SO4 --gt CuSO4 2HOH SO2

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HOMEWORK