You can identify a compound to be an alcohol when it has a hydrocarbon chain and a hydroxyl functional group or -OH group. Also, from the name, you can tell that it is an alcohol is the suffix -ol is present. Examples are ethanol and methanol. Alcohol is any organic substance that contains an hydroxyl group bonded to a carbon atom that is saturated. Alcohols can be classified as primary, secondary or tertiary depending on where the hydroxyl functional group is attached in the hydrocarbon chain. It is a primary alcohol when OH is attached to the first carbon atom. Secondary alcohol, and tertiary alcohols has a general formula CHROH and CR2OH, respectively where R represents a hydrocarbon chain.