[1] All three of these compounds are colorless to white granular solids at room temperature and pressure, but upon exposure to oxygen they may darken.
Similar to other phenols, the hydroxyl groups on the aromatic ring of a benzenediol are weakly acidic.
Each benzenediol can lose an H+ from one of the hydroxyls to form a type of phenolate ion.
The Dakin oxidation is an organic redox reaction in which an ortho- or para-hydroxylated phenyl aldehyde (−CH=O) or ketone (>C=O) reacts with hydrogen peroxide in base to form a benzenediol and a carboxylate.
Overall, the carbonyl group (C=O) is oxidized, and the hydrogen peroxide is reduced.