When ethanol reacts to form acetic acid, the carbon bound to the oxygen is and the oxidation state of the carbon changes from to

When ethanol reacts to form acetic acid, the carbon bound to the oxygen is oxidized and the oxidation state of the carbon changes from -1 to +3.
Oxidation is increase of oxidation number; oxidation number of carbon can be calculated by subtracting the sum of lone pairs and electrons it gains from bonds from the number of valence electrons.