Armstrong acid

Armstrong's acid
Names
	Preferred IUPAC name Naphthalene-1,5-disulfonic acid
	Other names Armstrong's acid
Identifiers
CAS Number	81-04-9 ;
3D model (JSmol)	Interactive image; Interactive image;
ChEBI	CHEBI:30890 ;
ChemSpider	6414 ;
ECHA InfoCard	100.001.199
PubChem CID	6666;
UNII	E8FPK78470 ;
CompTox Dashboard (EPA)	DTXSID5046982 ;
	InChI InChI=1S/C10H8O6S2/c11-17(12,13)9-5-1-3-7-8(9)4-2-6-10(7)18(14,15)16/h1-6H,(H,11,12,13)(H,14,15,16) Key: XTEGVFVZDVNBPF-UHFFFAOYSA-N ; InChI=1/C10H8O6S2/c11-17(12,13)9-5-1-3-7-8(9)4-2-6-10(7)18(14,15)16/h1-6H,(H,11,12,13)(H,14,15,16) Key: XTEGVFVZDVNBPF-UHFFFAOYAR;
	SMILES O=S(C2=CC=CC1=C(S(=O)(O)=O)C=CC=C12)(O)=O; O=S(=O)(O)c1cccc2c1cccc2S(=O)(=O)O;
Properties
Chemical formula	C10H8S2O6
Molar mass	288.299 g/mol
Appearance	colorless solid
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	corrosive
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Armstrong acid (naphthalene-1,5-disulfonic acid) is a fluorescent organic compound with the formula C₁₀H₆(SO₃H)₂. It is one of several isomers of naphthalenedisulfonic acid. It a colorless solid, typically obtained as the tetrahydrate. Like other sulfonic acids, it is a strong acid. It is named for British chemist Henry Edward Armstrong.