Redox Reactions

1. Redox Reactions

2. Redox Reactions • Redox is a term used for reduction – oxidation. • Redox reactions result from the competition for electrons between reacting particles! • Reduction and oxidation are reactions that are not independent from each other. These two reactions must occur simultaneously. • If one reactant is losing electrons then those electrons must be gained by the other reactant! Hence the term Redox! “LEO the lion says GER”

3. Redox Reactions • Oxidation represents a loss (or an apparent loss) of electrons. • Thus, oxidation is a reaction in which species lose electrons and gain oxidation number! “leo” lose electrons oxidation! “gon” gain oxidation number! leo gon RA

4. 0 Zn -2 O Redox Reactions Ex.1) What species is being oxidized in the reaction? _____ Zn + H2SO4 → ZnSO4 + H2 Ex.2) What species is being oxidized in the reaction? _____ 2 KClO3 → 2 KCl + 3 O2 0 +1 +6 -2 +2 +6 -2 0 leo gon RA +1 +5 -2 +1 -1 0 leo gon RA

5. 0 Cu -3 N Redox Reactions Ex.3) What species is being oxidized in the reaction? _____ 2 AgNO3 + Cu → 2 Ag + Cu(NO3)2 Ex.4) What species is being oxidized in the reaction? _____ 2 NH3 → N2 + 3H2 -1 +1 +5 -2 0 0 +2 +5 -2 leo gon RA -3 +1 0 0 leo gon RA

6. Redox Reactions • Reduction represents a gain (or an apparent gain) of electrons. • Thus, reduction is a reaction in which species gain electrons and lose oxidation number! “ger” gain electrons reduction! “lon” lose oxidation number! ger lon OA

7. 0 0 F2 Br2 Redox Reactions Ex.1) What species is being reduced in the reaction? _____ 2 K + F2 → 2 KF Ex.2) What species is being reduced in the reaction? _____ 2 KI + Br2 → 2 KBr + I2 0 0 +1 -1 ger lon OA +1 -1 0 +1 -1 0 ger lon OA

8. +2 +1 Cu Na Redox Reactions Ex.3) What species is being reduced in the reaction? _____ Pb + CuSO4 → PbSO4 + Cu Ex.4) What species is being reduced in the reaction? _____ 2 NaCl → 2 Na + Cl2 -2 -2 0 +2 +6 -2 +2 +6 -2 0 ger lon OA +1 -1 0 0 ger lon OA