Ethanoic acid is soluble in water. In fact, it is miscible with water in all proportions. This means that ethanoic acid and water can be mixed together in any ratio and will form a homogeneous mixture. The solubility of ethanoic acid in water is due to the fact that it is a polar molecule. The oxygen atom in the carboxyl group has a partial negative charge, while the hydrogen atoms have a partial positive charge. This allows ethanoic acid to form hydrogen bonds with water molecules, which makes it soluble in water.