Why are smaller alcohols soluble in water?

Question

Isaac Aronson · Accepted Answer

Dipole-dipole and hydrogen bond intermolecular forces pull the ethanol molecules apart from one another.

Small alcohols have attached #OH# groups which make the alcohols polar.

The polarity of the alcohol and polarity of the water create intermolecular forces, most notably dipole-dipole forces.

The positive and negative dipoles in the molecules align, tugging at one another and causing the alcohol molecules to break apart from one another in the water and dissolve.

Especially notable in alcohols is the presence of hydrogen bonding, the strongest type of dipole-dipole forces that occurs between a hydrogen atom and either an oxygen, nitrogen, or fluorine atom.

The left shows the hydrogen bond attractions in a solution of ethanol and water.

Zoe Alexander · Answer

undefined Smaller alcohols, such as methanol, ethanol, and propanol, are soluble in water due to their ability to form hydrogen bonds with water molecules. These alcohols contain a hydroxyl (-OH) group, which can hydrogen bond with the polar water molecules. This interaction allows the alcohol molecules to mix with water molecules, resulting in solubility. Additionally, smaller alcohols have fewer carbon atoms, making them more polar and enhancing their ability to interact with water molecules.