Tetra­ethyl­ammonium 4-hy­droxy­benzoate monohydrate

In the title compound, C(8)H(20)N(+)·C(7)H(5)O(3) (−)·H(2)O, the carboxyl­ate group is slightly out of the plane of the parent benzene ring, the C—C—C—O torsion angles being 2.3 (2) and 2.0 (2)°. The carboxyl­ate group and the hy­droxy group form O—H⋯O hydrogen bonds, generating a head-to-tail chain along the b axis. Neighbouring hydrogen-bonded chains are linked by the water mol­ecule, generating two independent O—H⋯O donor hydrogen bonds. The carboxyl­ate group thus constructs a hydrogen-bonded host layer parallel to (10[Image: see text]). The tetra­ethyl­ammonium cation is contained between these layers, forming a sandwich-like structure with an approximate inter­layer distance of 10.03 Å.