Pyrocatechol-3,5-disulfonic acid

4,5-Dihydroxybenzene-1,3-disulfonic acid

1,2-Dihydroxybenzene-3,5-disulfonic acid

1,2-Dihydroxy-3,5-benzenedisulfonic acid

4,5-dihydroxybenzene-1,3-disulphonic acid