CHM 501 Lecture

Oxidation/Reduction Reactions

Transfer of electrons from oxidized species (loses electrons) to reduced species (gains electrons)

Connections between structure/bonding and reactivity are less obvious than in acid/base chemistry.  Assignment of oxidation numbers is connected to Lewis structures and ion charge.

Review of balancing redox reactions

1. Separate into oxidation and reduction half-reactions

2. Balance atoms other than H and O by inspection

3. Balance O with water

4. Balance H with H+

5. Balance charge with e–

6. Adjust each half-reaction so that the same number of electrons is present

7. Add half-reactions and cancel common species

8. If the reaction is in base, neutralize any H+ with OH–

Balance the following redox reaction:

ReCl5(s) + H2O(l) Re2Cl92–(aq) + ReO4–(aq) + Cl–(aq) + H+(aq)

Details


HIO3(aq) + FeI2(aq) + HCl(aq) FeCl3(aq) + ICl(g) + H2O(l)

Details


CuSCN(aq) + KIO3(aq) + HCl(aq) CuSO4(aq) + KCl(aq) + HCN(aq) + ICl(g) + H2O(l)

Details