In ethanol C2H5OH , the carbon atom in the alcohol functional group -OH has an oxidation state of -1. This is because the oxygen atom is more electronegative than carbon and attracts the bonding electrons more strongly, resulting in a partial negative charge on the oxygen atom and a partial positive charge on the carbon atom.When ethanol undergoes oxidation, it can form either acetaldehyde CH3CHO or acetic acid CH3COOH , depending on the reaction conditions and the oxidizing agent used.In acetaldehyde, the carbon atom in the carbonyl group C=O has an oxidation state of +1. This is because the oxygen atom is more electronegative than carbon and attracts the bonding electrons more strongly, resulting in a partial negative charge on the oxygen atom and a partial positive charge on the carbon atom.In acetic acid, the carbon atom in the carboxyl group COOH has an oxidation state of +3. This is because the oxygen atoms are more electronegative than carbon and attract the bonding electrons more strongly, resulting in partial negative charges on the oxygen atoms and a partial positive charge on the carbon atom.So, the oxidation state of the carbon atom in ethanol before undergoing oxidation is -1, and after undergoing oxidation, it can be either +1 in acetaldehyde or +3 in acetic acid .