Predicting Redox Reactions by 29z84v


									                   Predicting Redox Reactions
  To review:
Reducing agent:      a substance that loses electrons to another
                     substance in a redox reaction (e- giver)
Oxidizing agent:     a substance that gains electrons from another
                     substance in a redox reaction (e- taker)
   Whether or not electrons are transferred depends on which
     substance has a stronger attraction to electrons

  Redox Tables
   When comparing cations (positive metal ions), the most
    reactive ions are the strongest oxidizing agents
   Example: Ag+ ion is more reactive than Cu2+ ion and therefore is
    the stronger oxidizing agent (better e- taker)
   When comparing metals, the most reactive metals are the
    strongest reducing agents
   Example: Cu is more reactive that silver and therefore is the
    stronger reducing agent (electron giver).

  Copy Table 3 into your notes (pg 676)
  NB: half reactions in redox tables are always written as reductions


  Redox spontaneity rule: a spontaneous redox reaction occurs only
  if the OA is above the RA on a redox table. The more active
  metal (stronger reducing agent) will stay/become an ion.

  Cu2+ + Zn          Cu + Zn2+ spontaneous (Zn becomes an ion)

  Zn2+ + Cu          n.r.         nonspontaneous (Zn2+ stays an ion)

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