1H-Benzimidazole-2-carboxylic acid monohydrate

1H-Benzimidazole-2-carboxylic acid crystallizes as the mono­hydrate, C₈H₆N₂O₂·H₂O, and the organic mol­ecule exists in a zwitterionic form, viz. 1H-benzimidazolium-2-carboxyl­ate. Hydrogen bonds connect the mol­ecules of acid and water into a two-dimensional network.