Oxidation-Reduction

Changes in Oxidation States

Consider reactions 1 through 6. Those carbon atoms undergoing change, as part of a functional group, are colored (red and blue). In the cases shown, each carbon atom has either been reduced or oxidized. Your job is to identify the change in oxidation state that has occurred for each of the colored carbons.

Reaction			Red Carbon	Blue Carbon
1. CH₃CH=CH₂	Br₂	CH₃CHBrCH₂Br	Reduced Oxidized	Reduced Oxidized
2. CH₃CH=CH₂	(i) B₂H₆ (ii) H₂O₂ , NaOH	CH₃CH₂CH₂OH	Reduced Oxidized	Reduced Oxidized
3. CH₃CH₂CH=O	NaBH₄	CH₃CH₂CH₂OH	Reduced Oxidized
4. CH₃CH₂CH=O	Ag⁽⁺⁾ H₂O , pH>8	CH₃CH₂CO₂H	Reduced Oxidized
5. CH₃COCH₂CO₂H	Heat	CH₃COCH₃ + O=C=O	Reduced Oxidized	Reduced Oxidized
6. H₂C=C(OH)C₂H₅	tautomerization	H₃CCOC₂H₅	Reduced Oxidized	Reduced Oxidized

This script written by William Reusch, Dept. of Chemistry, Michigan State University. Please send comments and corrections to whreusch@pilot.msu.edu.