Phosphoric acid, tseem hu ua orthophosphoric acid, yog ib qho inorganic acid feem ntau siv nyob rau hauv ntau yam lag luam. Nws muaj cov acidity me ntsis, nws cov tshuaj formula yog H3PO4, thiab nws qhov hnyav molecular yog 97.995. Tsis zoo li qee cov kua qaub tsis hloov pauv, phosphoric acid ruaj khov thiab tsis tawg yooj yim, ua rau nws muaj kev ntseeg siab rau ntau yam kev siv. Thaum phosphoric acid tsis muaj zog li hydrochloric, sulfuric, lossis nitric acids, nws muaj zog dua li acetic thiab boric acids. Tsis tas li ntawd, cov kua qaub no muaj cov yam ntxwv ntawm cov kua qaub thiab ua haujlwm tsis muaj zog tribasic acid. Nws yog tsim nyog sau cia tias phosphoric acid yog hygroscopic thiab yooj yim nqus dej los ntawm huab cua. Tsis tas li ntawd, nws muaj peev xwm hloov mus rau pyrophosphoric acid thaum rhuab, thiab tom qab poob dej tuaj yeem hloov mus rau metaphosphoric acid.