Methyl yellow
| Methyl yellow | |
|---|---|
 | |
| IUPAC name p-Dimethylaminoazobenzene | |
| Other names 4-Dimethylaminoazobenzene, DAB, N,N-Dimethyl-4-phenylazoaniline, N,N-Dimethyl-4-aminoazobenzene, Butter Yellow, Solvent Yellow 2, C.I. 11020 | |
| Identifiers | |
| CAS number | 60-11-7  |
| PubChem | 6053 |
| ChemSpider | 5829 |
| UNII | A49L8E13FD |
| EC number | 200-455-7 |
| ChEMBL | CHEMBL263116 |
| RTECS number | BX7350000 |
| Jmol-3D images | Image 1 |
| |
| |
| Properties | |
| Molecular formula | C14H15N3 |
| Molar mass | 225.289 g.mol-1 |
| Appearance | Yellow crystals |
| Melting point | 116 °C (decomposes) |
| Solubility in water | 13.6 mg.l-1 |
| log P | 4.58 |
| Hazards | |
| R-phrases | R25, R40 |
| S-phrases | S36/37, S45 |
| Main hazards | Toxic (T) |
| NFPA 704 |
 1
2
0
|
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Methyl yellow, or C.I. 11020, is a chemical compound which may be used as a pH indicator.
| Methyl yellow (pH indicator) | ||
| below pH 2.9 | above pH 4.0 | |
| 2.9 | ↔ | 4.0 |
In aqueous solution at low pH, methyl yellow appears red. Between pH 2.9 and 4.0, methyl yellow undergoes a transition, to become yellow above pH 4.0.
Additional indicators are listed in the article on pH indicators.
It is a possible carcinogen.[1]
As "butter yellow" the agent had been used as a food additive before its toxicity was recognized.[2]
References
- ↑ NIOSH Pocket Guide to Chemical Hazards 0220
- ↑ Opie, E. L. (1944). "The Pathogenesis of Tumors of the Liver Produced by Butter Yellow" (pdf). The Journal of Experimental Medicine 80 (3): 231–246. PMC 2135460. PMID 19871411.
See also
Structurally similar compounds:
External links
- International Chemical Safety Card 1498
- "para-dimethylaminoazobenzene". Inchem.
- CDC - NIOSH Pocket Guide to Chemical Hazards
- Chung, K. T.; Fulk, G. E.; Andrews, A. W. (1981). "Mutagenicity testing of some commonly used dyes" (pdf). Applied and Environmental Microbiology 42 (4): 641–648. PMC 244076. PMID 7039509.