Final answer:
The hybridization of a carbon atom in alcohol changes from sp³ to sp² when converted to an aldehyde. For the transition from an aldehyde to a carboxylic acid, the hybridization state remains sp². Thus, the answer is sp³ to sp²; sp² to sp².
Step-by-step explanation:
When an alcohol is converted into an aldehyde, the hybridization of the substituted carbon atom changes from sp³ to sp². In an alcohol, the carbon bonded to the -OH group is sp³ hybridized because it is bonded to three other atoms and has one lone pair from the hydroxyl oxygen.
Upon oxidation, the alcohol becomes an aldehyde, and the carbon changes to sp² hybridization due to the formation of a double bond with oxygen (C=O).
Moving from an aldehyde to a carboxylic acid, the hybridization remains sp², as both functional groups have a double bond with oxygen.
Therefore, the correct answer to how hybridization changes from alcohol to aldehyde and from aldehyde to carboxylic acid is a) sp³ to sp²; sp² to sp².