To determine the functional groups present in a compound with the molecular formula C3H6O using infrared spectroscopy, we need to consider the possible structures and their corresponding IR spectra.There are two main possibilities for the structure of a compound with the molecular formula C3H6O:1. An alcohol R-OH functional group: In this case, the compound would be a propanol isomer either 1-propanol or 2-propanol . The characteristic IR absorption for an alcohol functional group is a broad O-H stretching band around 3200-3600 cm-1.2. A carbonyl C=O functional group: In this case, the compound would be an aldehyde or a ketone. The possible structures are propanal an aldehyde or acetone a ketone . The characteristic IR absorption for a carbonyl functional group is a strong C=O stretching band around 1650-1750 cm-1.By analyzing the IR spectrum of the compound, you can determine which of these functional groups is present. If you see a broad O-H stretching band, it is likely an alcohol. If you see a strong C=O stretching band, it is likely a carbonyl-containing compound either an aldehyde or a ketone .