114510

Methyl Orange

ACS reagent, Dye content 85 %

• Synonym(s): 4-[4-(Dimethylamino)phenylazo]benzenesulfonic acid sodium salt, Acid Orange 52, Helianthin, Orange III
• Empirical Formula (Hill Notation): C₁₄H₁₄N₃NaO₃S
• CAS Number: 547-58-0
• Molecular Weight: 327.33
• Colour Index Number: 13025
• Beilstein/REAXYS Number: 4732884
• EC Number: 208-925-3
• MDL number: MFCD00007502
• UNSPSC Code: 12171500
• PubChem Substance ID: 24847177
• NACRES: NA.47

Properties

• grade: ACS reagent
• form: powder
• composition: Dye content, 85%
• technique(s): titration: suitable
• color: orange
• pH: 3.0-4.4, pink to yellow
• visual transition interval: 3.2-4.4, red to yellow
• mp: >300 °C
• λmax: 505 nm
• application(s): diagnostic assay manufacturing; hematology; histology
• storage temp.: room temp
• SMILES string: [Na+].CN(C)c1ccc(cc1)\N=N\c2ccc(cc2)S([O-])(=O)=O
• InChI: 1S/C14H15N3O3S.Na/c1-17(2)13-7-3-11(4-8-13)15-16-12-5-9-14(10-6-12)21(18,19)20;/h3-10H,1-2H3,(H,18,19,20);/q;+1/p-1/b16-15+;
• InChI key: STZCRXQWRGQSJD-GEEYTBSJSA-M

Description

General description

Methyl orange (C.I. 13025) is the sodium salt of p-dimethylaminoazobenzenesulfonic acid.It is an orange-colored synthetic dye, which changes color depending on the pH of the solution. It develops a red color in acidic solution and yellow color in basic solution.

Application

Methyl orange is used as a-

• pH indicator in the cell sap
• counterstain to crystal violet in staining pollen tubes
• component of a polychrome histological stain
• solution indicator, such as in assays of oxalic and malonic acids
• in other biomedical applications that include use in film dosimeters and as a reagent for the assay of bromide ions.

Biochem/physiol Actions

Methyl Orange is an azo dye which works as a pH indicator.

Safety Information

• pictograms: GHS06
• signalword: Danger
• hcodes: H301
• pcodes: P301 + P330 + P331 + P310
• Hazard Classifications: Acute Tox. 3 Oral
• Storage Class: 6.1C - Combustible acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Faceshields, Gloves, type P2 (EN 143) respirator cartridges