National League for Nursing (NLN PAX) Practice Exam

The primary function of the hydroxyl group in alcohols is to increase solubility in water. The hydroxyl group, which consists of an oxygen atom bonded to a hydrogen atom (–OH), is polar due to the electronegativity of oxygen. This polarity allows hydroxyl groups to form hydrogen bonds with water molecules, resulting in increased solubility of the alcohol in water.

This solubility is essential in many biological and chemical processes, especially in the context of metabolism and the transport of substances in living organisms. Alcohols with hydroxyl groups are often more soluble in aqueous solutions compared to hydrocarbons lacking polar functional groups.

Other options may reference various functions associated with organic compounds, but when it comes to alcohols, the increase in solubility due to the presence of the hydroxyl group is the most significant and distinctive characteristic.