Meta-xylene
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| Names | |||
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Preferred IUPAC name
1,3-Xylene
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Systematic IUPAC name
1,3-Dimethylbenzene
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| Other names
m-Xylene
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| Identifiers | |||
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3D model (JSmol)
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.003.252 | ||
| KEGG | |||
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PubChem CID
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| RTECS number | ZE2275000 | ||
| UNII | |||
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| Properties | |||
| C8H10 | |||
| Molar mass | 106.16 g/mol | ||
| Appearance | Colorless liquid | ||
| Density | 0.86 g/mL | ||
| Melting point | −48 °C (−54 °F; 225 K) | ||
| Boiling point | 139 °C (282 °F; 412 K) | ||
| insoluble | |||
| Solubility in ethanol | very soluble | ||
| Solubility in diethyl ether | very soluble | ||
| Vapor pressure | 9 mmHg (20°C) | ||
| -76.56·10−6 cm3/mol | |||
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Refractive index (nD)
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1.49722 | ||
| Viscosity | 0.8059 cP at 0 °C 0.6200 cP at 20 °C |
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| 0.33-0.37 D | |||
| Hazards | |||
| Main hazards | Harmful or fatal if swallowed. Vapor harmful. Flammable liquid and vapor. | ||
| Safety data sheet |
See: data page External MSDS |
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| R-phrases (outdated) | R10 R20 R21 R38 | ||
| S-phrases (outdated) | S25 | ||
| NFPA 704 | |||
| Flash point | 27 °C (81 °F; 300 K) | ||
| 527 °C (981 °F; 800 K) | |||
| Explosive limits | 1.1%-7.0% | ||
| 100 ppm (TWA), 150 ppm (STEL) | |||
| Lethal dose or concentration (LD, LC): | |||
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LCLo (lowest published)
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2010 ppm (mouse, 24 hr) 8000 ppm (rat, 4 hr) |
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| US health exposure limits (NIOSH): | |||
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PEL (Permissible)
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TWA 100 ppm (435 mg/m3) | ||
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REL (Recommended)
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TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3) | ||
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IDLH (Immediate danger)
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900 ppm | ||
| Related compounds | |||
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Related aromatic
hydrocarbons |
benzene toluene o-xylene p-xylene |
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| Supplementary data page | |||
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Refractive index (n), Dielectric constant (εr), etc. |
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Thermodynamic
data |
Phase behaviour solid–liquid–gas |
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| UV, IR, NMR, MS | |||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |||
m-Xylene (meta-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The m- stands for meta-, indicating that the two methyl groups in m-xylene occupy positions 1 and 3 on a benzene ring. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, o-xylene and p-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable.
Petroleum contains about 1 weight percent xylenes.
The major use of meta-xylene is in the production of isophthalic acid, which is used as a copolymerizing monomer to alter the properties of polyethylene terephthalate (PET). The conversion m-xylene to isophthalic acid entails catalytic oxidation. meta-Xylene is also used as a raw material in the manufacture of 2,4- and 2,6-xylidine as well as a range of smaller-volume chemicals.
Xylenes are not acutely toxic, for example the LD50 (rat, oral) is 4300 mg/kg. Effects vary with animal and xylene isomer. Concerns with xylenes focus on narcotic efffects.
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