Difference between revisions of "Naphthalene"
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It can also be destroyed with [[Fenton's reagent]]. However, the heat of the oxidation may give off various side products, so neutralize small amounts, outside. A UV lamp can be used to improve the Fenton oxidation process. | It can also be destroyed with [[Fenton's reagent]]. However, the heat of the oxidation may give off various side products, so neutralize small amounts, outside. A UV lamp can be used to improve the Fenton oxidation process. | ||
+ | |||
+ | ==Gallery== | ||
+ | <gallery widths="200" position="center" columns="4" orientation="none"> | ||
+ | Naphthalene_sublimated_crystals.jpg|Sublimated naphthalene crystals under the microscope | ||
+ | </gallery> | ||
==References== | ==References== |
Revision as of 08:47, 11 August 2020
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![]() Mothballs containing naphthalene
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Names | |
---|---|
IUPAC name
Naphthalene
| |
Preferred IUPAC name
Naphthalene | |
Systematic IUPAC name
Bicyclo[4.4.0]deca-1,3,5,7,9-pentaene Bicyclo[4.4.0]deca-2,4,6,8,10-pentaene | |
Other names
Camphor tar
Naphthalin White tar | |
Identifiers | |
Jmol-3D images | Image |
| |
Properties | |
C10H8 | |
Molar mass | 128.17 g/mol |
Appearance | White volatile solid |
Odor | Strong, aromatic |
Density | 1.145 g/cm3 (15.5 °C) 1.0253 g/cm3 (20 °C) 0.9625 g/cm3 (100 °C) |
Melting point | 80.2 °C (176.4 °F; 353.3 K) |
Boiling point | 217.9 °C (424.2 °F; 491.0 K) |
0.00190 g/100 ml (10 °C) 0.00316 g/100 ml (25 °C) 0.00439 g/100 ml (34.5 °C) 0.00809 g/100 ml (50 °C) 0.02381 g/100 ml (73.4 °C) | |
Solubility | Soluble in glacial acetic acid, liq. ammonia, aniline, benzene, CS2, CCl4, ethanol, olive oil, liq. SO2, toluene, turpentine |
Solubility in acetic acid | 6.8 g/100 g (6.75 °C) 13.1 g/100 g (21.5 °C) 31.1 g/100 g (42.5 °C) 111 g/100 g (60 °C) |
Solubility in butyric acid | 13.6 g/100 g (6.75 °C) 22.1 g/100 g (21.5 °C) 131.6 g/100 g (60 °C) |
Solubility in carbon disulfide | 83.3 g/100 ml |
Solubility in chloroform | 19.5 g/100 g (0 °C) 35.5 g/100 g (25 °C) 49.5 g/100 g (40 °C) 87.2 g/100 g (70 °C) |
Solubility in ethanol | 5 g/100 g (0 °C) 11.3 g/100 g (25 °C) 19.5 g/100 g (40 °C) 179 g/100 g (70 °C) |
Vapor pressure | 8.64 Pa (20 °C) 23.6 Pa (30 °C) 0.93 kPa (80 °C) 2.5 kPa (100 °C) |
Viscosity | 0.964 cP (80 °C) 0.761 cP (100 °C) 0.217 cP (150 °C) |
Thermochemistry | |
Std molar
entropy (S |
167.39 J·mol-1·K-1 |
Std enthalpy of
formation (ΔfH |
78.53 kJ/mol |
Hazards | |
Safety data sheet | Sigma-Aldrich |
Flash point | 80 °C |
Lethal dose or concentration (LD, LC): | |
LD50 (Median dose)
|
1800 mg/kg (rat, oral) 490 mg/kg (rat, oral) 1200 mg/kg (guinea pig, oral) 533 mg/kg (mouse, oral) |
Related compounds | |
Related compounds
|
Tetralin Decalin |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
Naphthalene is an organic compound with the chemical formula C10H8. It is the simplest polycyclic aromatic hydrocarbon.
Contents
Properties
Chemical
Naphthalene can react with halogens, such as chlorine to form 1-chloronaphthalene, without requiring a catalyst, unlike in the case of benzene. Likewise, whereas both benzene and naphthalene can be alkylated using Friedel–Crafts reactions, naphthalene can also be alkylated by reaction with alkenes or alcohols, with sulfuric or phosphoric acid as the catalyst.
Physical
Naphthalene is a white crystalline solid with a characteristic odor that is detectable at low concentrations. It is insoluble in water, but soluble in other organic solvents, especially closer to their boiling point.
Availability
Some mothballs, especially the older types tend to contain naphthalene, the exact concentration depending on the product. Naphthalene can be extracted via sublimation. Always check the label, as most common mothballs contain 1,4-dichlorobenzene.
Naphthalene and 1,4-dichlorobenzene are never found together, as they react.
Mothballs and other products containing naphthalene have been banned within the EU since 2008. However, you may still find naphthalene powder/balls in some second-hand hardware stores, as "odor pellets". The naphthalene content is between 80-95 % and the impurities sometimes render the naphthalene non-flammable.
Preparation
Naphthalene can be extracted from coal tar, via sublimation and purification.
Projects
- Phthalic anhydride synthesis
- Dialin synthesis
Handling
Safety
Naphthalene is known to be toxic to red blood cells and it's considered a possible carcinogenic. Its strong smell is considered obnoxious and it's best to handle it outside or in a well ventilated area (like a fume hood).
Storage
Naphthalene should be stored in hermetically sealed bottles and kept in a cold place as it will slowly sublime and deposit on the cap interior. Instant coffee and paint cans are good storage containers.
Disposal
Burning naphthalene is an attractive disposal method, but will result in lots of soot, VOCs, PAHs, other aromatics, carbon monoxide, as well as fumes of unburnt naphthalene being generated. The resulting smoke has a strong smell, like in the case of most aromatics, and burning may not be a suitable method of disposal in a densely populated area. While this is not an issue with small amounts, a special incinerator may be required for bulk quantities.
It can also be destroyed with Fenton's reagent. However, the heat of the oxidation may give off various side products, so neutralize small amounts, outside. A UV lamp can be used to improve the Fenton oxidation process.
Gallery
References
Relevant Sciencemadness threads
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