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Good Morning Ladies!

Good Morning Ladies!. Questions before the test? TEST. In both fission and fusion reactions, energy is…. RELEASED because…. E = m c 2 Energy = mass x speed of light squared Mass is converted to energy.

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Good Morning Ladies!

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  1. Good Morning Ladies! • Questions before the test? • TEST

  2. In both fission and fusion reactions, energy is… RELEASED because… • E =mc2 • Energy = mass x speed of light squared • Mass is converted to energy

  3. 100 g samples of both radium-226 and radon-222 were left in a chemical laboratory in 1950. Which sample poses the least risk today? Half-life of radium-226 is 1600y Half-life of radon-222 is 3.82d • radon-222 because it has a shorter half-life • radon-222 because it decays faster

  4. Good Afternoon Ladies! • Questions before the test? • TEST ……………. 3. Begin Oxidation-Reduction Reactions Unit

  5. In both fission and fusion reactions, energy is… RELEASED because… • E =mc2 • Energy = mass x speed of light squared • Mass is converted to energy

  6. 100 g samples of both radium-226 and radon-222 were left in a chemical laboratory in 1950. Which sample poses the least risk today? Half-life of radium-226 is 1600y Half-life of radon-222 is 3.82d • radon-222 because it has a shorter half-life • radon-222 because it decays faster

  7. Good Morning Ladies! • Prayer • Regents Review Resources • Begin Oxidation-Reduction Reactions Unit • What are oxidation-reduction reactions? • Assigning oxidation numbers HW: Redox 1 DUE MONDAY Also: Simulating Half-Life Lab DUE next Friday

  8. Oxidation-Reduction Reactions

  9. *What kind of chemical reaction is responsible for burning, rusting, bleaching clothes, powering your cell phone as well as your body, and giving fireflies their glow? • Oxidation-Reduction Reactions, also called • REDOX reactions

  10. I. What are Redox Reactions? • Redox reactions involve the transfer of ELECTRONS (e–) between different atoms Na + Cl → Na + Cl

  11. Oxidation Reduction

  12. * CONSERVATION OF CHARGE: oxidation and reduction happen simultaneously (at the same time) – you can’t have one without the other

  13. Remember: LEO the lion says GER (or LEO the liger says GER) • LOSING ELECTRONS is OXIDATION • GAINING ELECTRONS is REDUCTION

  14. Good Afternoon Ladies! • Determining if a reaction is redox • Assigning oxidation numbers HW: Redox 1 DUE MONDAY Also: Simulating Half-Life Lab DUE next Friday

  15. II. Determining if a reaction is a redox reaction • If the oxidation number/state of an atom changes from reactant to product, a redox reaction has occurred *Note: Double replacement reactions are NOT redox reactions

  16. A. Assigning Oxidation Numbers(listed on the Periodic Table) 1. If a species is all by itself (not combined with a different element), its oxidation number is ZERO Ex: Mg O2 S2 Cu H2

  17. A. Assigning Oxidation Numbers(listed on the Periodic Table) 2. In a polyatomic ion, the elements’ oxidation numbers add up to equal the CHARGE on the ion * SOS: you must multiply the Subscript by the Oxidation number to get the Sum NH4+ ClO–

  18. A. Assigning Oxidation Numbers(listed on the Periodic Table) 2. In a polyatomic ion, the elements’ oxidation numbers add up to equal the CHARGE on the ion * SOS: you must multiply the Subscript by the Oxidation number to get the Sum SO32– SO42–

  19. A. Assigning Oxidation Numbers(listed on the Periodic Table) 3. In a compound, the oxidation numbers of the elements add up to ZERO (compounds are neutral) * SOS: you must multiply the Subscript by the Oxidation number to get the Sum NaCl

  20. A. Assigning Oxidation Numbers(listed on the Periodic Table) 3. In a compound, the oxidation numbers of the elements add up to ZERO (compounds are neutral) • SOS: you must multiply the Subscript by the Oxidation number to get the Sum NH4Cl

  21. A. Assigning Oxidation Numbers(listed on the Periodic Table) 3. In a compound, the oxidation numbers of the elements add up to ZERO (compounds are neutral) • SOS: you must multiply the Subscript by the Oxidation number to get the Sum H2SO3

  22. More Examples a.)  What is the oxidation number of chlorine in iron (III) chloride?

  23. More Examples b.) What is the oxidation state of chromium in potassium chromate?

  24. B. Checking for Changes in Oxidation Numbers 2 Na (s) + Cl2 (g) → 2NaCl (s) • The oxidation # on Na changes from 0 to +1 • Na loses electrons • Na is oxidized • Na is the reducing agent • The oxidation # on Cl changes from 0 to –1 • Clgains electrons • Cl is reduced • Cl is the oxidizing agent

  25. B. Checking for Changes in Oxidation Numbers 2Mg (s) + O2 (g) → 2MgO (s) • The oxidation # on Mg changes from 0 to +2 • Mg loses electrons • Mg is oxidized • Mg is the reducing agent • The oxidation # on O changes from 0 to –2 • O gains electrons • O is reduced • O is the oxidizing agent

  26. OrangePacket • #s 1, 21, 23, 25

  27. Good Morning Ladies! • Prayer • Review Videos on Wikispace! • Trade & Grade Redox 1 (collect) • Writing Oxidation & Reduction Half-Reactions HW: Redox 2 DUE WEDNESDAY Reminder: Simulating Half-Life Lab DUE FRIDAY

  28. Good Afternoon Ladies! • Review Videos on Wikispace! • Trade & Grade Redox 1 (collect) • Writing Oxidation & Reduction Half-Reactions HW: Redox 2 DUE WEDNESDAY Reminder: Simulating Half-Life Lab DUE FRIDAY

  29. a.) Zn + 2HCl → ZnCl2 + H2

  30. b.) 4Al + 3O2 → 2Al2O3

  31. c. For soldiers on the front lines or on special remote missions, a hot meal can make a big difference. Instead of building a fire or carrying a stove with them, soldiers simply break open a bag and mix some magnesium metal with water to heat their food. This reaction is an example of a redox reaction, producing magnesium hydroxide, hydrogen gas, and heat as products. In the space below, write the oxidation and reduction half-reactions.

  32. Whiteboard Practice Write the oxidation and reduction half-reactions for the following redox reactions Zn + HNO3  Zn(NO3)2 + NO2 + H2O Sn + HNO3 + H2O  H2SnO3 + NO NaClO + H2S  NaCl + H2SO4

  33. Orange Packet #s 2, 3, 19, 20, 22, 24, 26-30, 32-35

  34. Good Morning Ladies! (TUES) • Prayer • Gummy Bear Sacrifice • Breathalyzer Demo • Balancing Redox Reactions • Pass back Nuclear Chemistry Test HW: Redox 2 DUE TOMORROW Reminder: Simulating Half-Life Lab DUE FRIDAY

  35. In the presence of oxygen, iron forms iron (III) oxide, more commonly known as rust. In the space below, write the balanced equation for the chemical process of the corrosion of iron using the oxidation and reduction half-reaction method.

  36. What causes fruit to turn brown? • Oxidation of compounds in fruit after exposure to oxygen in the air causes a change of color (browning) of fruit

  37. Oxidation (losing electrons) is a process that can be very damaging to living things. • results in the creation of free radicals, which are chemical species that have unpaired electrons (they are unhappy – they don’t have a completed valence shell) • free radicals will rip electrons away from other compounds in living things, such as proteins or molecules of DNA, causing damage which can lead to cancer • Antioxidants get rid of free radicals • Vitamins A, C, and E are antioxidants

  38. Good Morning Ladies! (WED) Please place your Redox 2 HW in the bin • Prayer • Two Types of Electrochemical Cells • Voltaic cells • Electrolytic cells Reminder: Simulating Half-Life Lab DUE FRIDAY Heads up HW: Redox 3 DUE TUESDAY *Redox Unit TEST next WEDNESDAY

  39. Good Afternoon Ladies! (WED) Please place your Redox 2 HW in the bin • Two Types of Electrochemical Cells • Voltaic cells • Electrolytic cells Reminder: Simulating Half-Life Lab DUE FRIDAY Heads up HW: Redox 3 DUE TUESDAY *Redox Unit TEST next WEDNESDAY

  40. V. Electrochemical Cells A. Use REDOX reactions to convert chemical energy into electrical energy OR convert electrical energy into chemical energy

  41. 1. Voltaic (Galvanic) Cells =batteries a.) SPONTANEOUSredox reactions – NO energy put in (energy is released) Use Table J to determine what is oxidized and what is reduced Higher on Table J is OXIDIZED Lower on Table J is REDUCED

  42. *Parts to Know* • Electrodes: the places where oxidation or reduction happens • Anode: the site of oxidation(An Ox) • Cathode: the site of reduction(Red Cat) • Wire: electrons flow through the wire from the anode (–) to the cathode (+) • Salt bridge: allows IONS to flow between the electrodes to keep the charges balanced

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