3. Identify the pairs of compounds that are constitutional isomers, identical compounds, or entirely different compounds (i.e., do not share the same molecular formula and therefore are not isomers). and and and (1) 9 H2COCH2CH2CH3 and H3CH2COCH3CH3 (b) (4) Classify the following compounds by their functional groups. Choose from the following alcohol. aldehyde, alkane, alkene, alkyne, amide, amine, carboxylic acid, ester, ether, or ketone. Circle the relevant functional group. a 0 CH3CH3OCH4