The word hydrolysis is applied to chemical reactions in which a substance reacts with water. In organic chemistry, the products of the reaction are usually molecular, being formed by combination with H and OH groups (e.g., hydrolysis of an ester to an alcohol and a carboxylic acid). In inorganic chemistry, the word most often applies to cations forming soluble hydroxide or oxide complexes with, in some cases, the formation of hydroxide and oxide precipitates.