Redox Rxns

1
Chapter 4 II

• Redox Rxns

2
Oxidation-Reduction Rxns. (Redox)

• involves a transfer of electrons between two
  species.

3
Oxidation

• an increase in charge
• Fe(s) ? Fe3
• (loses e-)

4
Reduction

• a decrease in charge
• Cu2(aq) ? Cu(s)
• (gains e-)

5
Balancing Redox Half-Rxns

• Half Rxn portion of a net ionic equation that
  identifies a change in the charge of the species.

6
Goals for Balancing Half-Rxns

• Balance same type number of atoms
• Have the same charge on both sides
• For balancing, see handout

7
Half-Rxns

• Ni2 ? Ni3
• I2 ? I-
• MnO4- ? Mn2
• Cr2O72- ? Cr3

8
Oxidation Reducing Agents

• OA (e- acceptor) causes the other species to
  lose e- or oxidize.
• RA (e- donor) causes the other species to gain
  e- or reduce.

9

• Zn 2H ? Zn2 H2