Question

Can primary alcohols be oxidized to form either aldehydes or ketones?

Answer 1

No. Primary alcohols can only be oxidized to form aldehydes or carboxylic acids. For instance, using chromic acid (to get a carboxylic acid), or using PCC in dichloromethane (to get an aldehyde).

Only secondary alcohols can be oxidized to form ketones, because by definition, a ketone requires a carbonyl oxygen on a non-terminal carbon, and a primary alcohol must have a hydroxyl oxygen on the terminal carbon.

See this answer for further information.