Methyl yellow

Methyl yellow
Names
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
60-11-7 Yes
ChEMBL ChEMBL263116 Yes
ChemSpider 5829 Yes
EC number 200-455-7
Jmol-3D images Image
PubChem 6053
RTECS number BX7350000
UNII A49L8E13FD Yes
Properties
Molecular formula
 C14H15N3
Molar mass 225.29 g·mol−1
Appearance Yellow crystals
Melting point 111–116 °C (232–241 °F; 384–389 K)
decomposes[1]
13.6 mg/l
log P 4.58
Hazards
Main hazards Carcinogen[2]
GHS pictograms [1]
GHS signal word Danger
H301, H351[1]
P281, P301+310[1]
EU classification T
R-phrases R25, R40
S-phrases S36/37, S45
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
1
2
0
US health exposure limits (NIOSH):
OSHA-regulated carcinogen[2]
Ca[2]
Ca [N.D.][2]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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.

Safety

It is a possible carcinogen.[3] As "butter yellow", the agent had been used as a food additive before its toxicity was recognized.[4] The result from consuming such chemicals is tumors on the liver.

See also

Structurally similar compounds:

References

  1. ↑ 1.0 1.1 1.2 1.3 Dimethyl yellow
  2. ↑ 2.0 2.1 2.2 2.3 "NIOSH Pocket Guide to Chemical Hazards #0220". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ "NIOSH Pocket Guide to Chemical Hazards #0220". National Institute for Occupational Safety and Health (NIOSH).
  4. ↑ 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. doi:10.1084/jem.80.3.231. PMC 2135460. PMID 19871411.

External links