We can match these items as follows;
R-OH | Primary alcohol
R-COH-R | Secondary alcohol
R-CHO | Aldehyde
R-COOH | Carboxylic acid
R-CO-R | Ketone
R-COO-R | Esters
How to match the items
A secondary alcohol is a type of alcohol molecule where the carbon atom holding the hydroxyl (-OH) group is bonded to two other carbon atoms.
They have intermediate boiling points and solubilities compared to primary and tertiary alcohols. This is because they can form hydrogen bonds with water but are also bulkier due to the two attached carbon atoms.