Appearance: colorless acicular crystallization or leaf.Easily soluble in water and ethanol, insoluble in ether and carbon                                 disulfide, slightly soluble in benzene. 

Purpose: by alkali fusion phenol, also used in the system between benzodiazepines, etc., often used as a catalyst in the                      esterification and dehydration reaction.
                 Used as experimental reagent, catalyst, and also used in organic synthesis, and phenol manufacture.
                 Benzene sulfonic acid used for oilfield water injection, can remove formation plugging, increase the formation                        permeability.As acid acidification of injection Wells, the characteristics of benzene sulfonic acid with carbonate                        reaction is slow, and the greater the concentration, reaction rate slower, acidification profound formation,                                  compared with hydrochloric acid, benzene sulfonic acid (and mixed aryl sulfonic acid) the period of validity,                              corrosive small, the use of safe. Esterification and dehydration reaction of benzene sulfonic acid was used as                        catalyst and the curing agent of foundry industry.
                 Inspection the ammonium salt and potassium. The determination of zinc. Organic synthesis. Manufacture of                          phenol and resorcinol. Catalyst. Used as dehydration catalyst, resin curing agent, and electroplating additives,                         also can be used as dye intermediates.