C.I. 13025 (Acid orange 52)
Methyl orange is a pH indicator frequently used in titrations because of its clear and distinct colour change. Because it changes colour at the pH of a midstrength acid, it is usually used in titrations for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but has a sharper end point.
Minimum Assay: 95%
Molecular Formula: C14H14N3NaO3S
Molecular Weight: 327.34 g/mol
Melting Point: >300°C
Absorptivity (pH 3.0) 501-504nm: 1050-1150
Absorptivity (pH 4.4) 467-471nm: 750-850
Loss on Drying: <5%
Hazard Class: 6.1
Packing Group: 3
Hazard Phrases: Toxic if swallowed.
Prec Phrases: IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician. Rinse mouth. Do NOT induce vomiting.
Cas No: 547-58-0
Einecs No: 208-925-3