Which ester is formed when octyl alcohol is combined with acetic acid in the presence of an acid and heat? octyl ester octanol octyl acetate acetyl octylate What is the difference between a ketone and an aldehyde? In an aldehyde, the carbonyl is bonded between two "R" groups. In an aldehyde, the carbonyl is directly bonded to a hydroxyl group In an aldehyde, the carbonyl is directly bonded to a nitrogen atom. In an aldehyde, the carbonyl is directly bonded to a hydrogen atom.