2. In a hydroxyl group, a hydrogen atom is bonded to an oxygen atom, which in turn is bonded to the carbon skeleton of the organic molecule. Organic compounds containing hydroxyl groups are called alcohols, and their specific names usually end in -ol, as in ethanol, the drug present in alcoholic beverages. In a structural formula, the hydroxyl group is usually abbreviated by omission of the covalent bond between the oxygen and hydrogen, and is written as -OH or HO-. (Do not confuse this functional group with the hydroxide ion, OH(- ion), formed by the dissociation of bases such as sodium hydroxide.) The hydroxyl group is polar as a result of the electronegative oxygen atom drawing electrons toward itself. Consequently, water molecules are attracted to the hydroxyl group, and this helps dissolve organic compounds containing such groups. Sugars, for example, owe their solubility in water to the presence of hydroxyl groups.