Hydroquinone, organic compound, white crystal. It is mainly used for making black and white developing agent, anthraquinone dye, azo dye, rubber antiaging agent, stabilizer and antioxidant. Photometric determination of phosphorus, magnesium, niobium, copper, silicon and arsenic. Determination of iridium by polarography and volumetric method. Reductants for heteropoly acids, copper and gold. Examine phosphate, tungstate, nitrate, nitrite, selenium and tellurium. Developer.