The molecule is the hydrate of tetrahydroxy-1,4-benzoquinone. The number of water molecules of crystallization (n) is variable, although most commonly the dihydrate (shown in the diagram) is formed in the solid phase. It contains a tetrahydroxy-1,4-benzoquinone.
2,3,5,6-tetrahydroxycyclohexa-2,5-diene-1,4-dione;dihydrate