naphthalene-1,5-disulfonic acid

naphthalene-1,5-disulfonic acid

[′naf·thə‚lēn ¦wən ¦fīv ‚dī·səl′fän·ik ′as·əd] (organic chemistry) C10H6-(SO3H)2 White crystals, decomposing when heated; used to make dyes. Also known as Armstrong's acid.