Styphnic acid
1197753
220364815
2008-06-19T14:34:33Z
Rickjpelleg
172198
/* Chembox */ added [[UN number]]s
{{Chembox new
| Name = Styphnic acid
| ImageFile = Styphnic acid.png
<!-- | ImageSize = 150px -->
| ImageName = Styphnic acid
| IUPACName = 2,4,6-trinitrobenzene-1,3-diol
| Section1 = {{Chembox Identifiers
| CASNo = 82-71-3
| UNNumber = [[List of UN Numbers 0201 to 0300|0219]] – ''Dry or wetted with < 20% water/alcohol''<br/>[[List of UN Numbers 0301 to 0400|0394]] – ''Wetted with >= 20% water/alcohol''
| SMILES = OC1=C([N+]([O-])=O)C(O)=C<br />([N+]([O-])=O)C=C1[N+]([O-])=O
}}
| Section2 = {{Chembox Properties
| Formula = C<sub>6</sub>H<sub>3</sub>N<sub>3</sub>O<sub>8</sub>
| MolarMass = 245.11 g/mol
| Density = 1.829 g/cm<sup>3</sup>
| MeltingPt = 180 °C
| BoilingPt = dec.
}}
}}
'''Styphnic acid''', or 2,4,6-trinitro-1,3-benzenediol, is a yellow [[astringent]] [[acid]] that forms hexagonal [[crystal]]s. It is used in the manufacture of [[dye]]s, [[pigment]]s, [[ink]]s, [[medicine]]s, and [[explosive]]s such as [[lead styphnate]]. It is itself a sensitive explosive, similar to [[picric acid]].
==Preparation and chemistry==
It may be prepared by the nitration of [[resorcinol]] with a mixture of [[nitric acid|nitric]] and [[sulfuric acid]] <ref>http://www.roguesci.org/chemlab/energetics/styphnic_acid.html</ref>.
This compound is an example of a trinitro [[Phenols|phenol]].
Like [[picric acid]], it is a moderately strong acid, displacing carbon dioxide from solutions of [[sodium carbonate]] for example.
It may be reacted with weakly basic oxides such as those of lead and silver to form the corresponding salts.
The solubility of [[picric acid]] and styphnic acid in water is far less than the non nitrated phenol and less than the corresponding mono and di nitro compounds so they may be purified by fractional crystallisation.
==References==
<references/>
[[Category:Nitro compounds]]
[[Category:Phenols]]
[[Category:Explosive chemicals]]
[[de:Styphninsäure]]
[[it:Acido stifnico]]
[[lv:Stifnīnskābe]]