CHEM 1E03 Lecture Notes - Lecture 19: Oxidation State

• School: McMaster University
• Department: Chemistry
• Course: CHEM 1E03
• Professor: Randall Dumont; Linda Davis

Document Summary

Oxidation agents: an element who"s oxidation number decreases (loses electrons, higher oxidizing number = stronger oxidizing agent, reduction reactions have the balancing electrons on the left. Reducing agents: an element who"s oxidation number increases (gains electrons, lower oxidation number = stronger reducing agent, oxidation reactions have the balancing electrons on the right. Example basic: mno4- + i- mno2 + i2. Oxidation numbers in order: +7, -2, -1, +4, -2, 0. Mno4- + 3e- mno2 + 2h20 add 2 water molecules so each side 4o. 4h+ + mno4- + 3e- mno2 + 2h20. 4oh- + 4h+ + mno4- + 3e- mno2 + 2h20+ 4oh- 4h2o + mno4- + 3e- mno2 + 2h20+ 4oh- Therefore by cancellation: 6i- + 4h2o + 2mno4 3i2 + 2mno2 + 8oh- Example acidic: h2o2 + al h2o + al3+ Oxidation numbers in order: +1, -1, 0, +1, -2, -3.