Ammonium perchlorate

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Ammonium perchlorate
Ammonium perchlorate
Unit cell of the crystal structure
Ammonium perchlorate 100g.jpg
Identifiers
CAS number7790-98-9 YesY
ChemSpider23041 YesY
EC number232-235-1
UN number1442
RTECS numberSC7520000
Jmol-3D imagesImage 1
Properties
Molecular formulaNH4ClO4
Molar mass117.49 g/mol
AppearanceWhite Crystalline [1]
Density1.95 g/cm3
Melting pointExothermic decomposition before melting at >200 °C[2]
Solubility in water11.56 g/100 mL (0 °C)
20.85 g/100 mL (20 °C)
57.01 g/100 mL (100 °C)
SolubilitySoluble in Methanol
partially soluble in Acetone
insoluble in Ether
Structure
Crystal structureOrthorhombic (< 513 K)
Cubic (> 513 K)
Hazards
MSDSExternal MSDS [3]
EU Index017-009-00-0
EU classificationOxidant (O)
R-phrasesR9, R44
S-phrases(S2), S14, S16, S27, S36/37
NFPA 704
NFPA 704.svg
1
2
2
OX
Autoignition temperature240 °C; 464 °F; 513 K
Related compounds
Other anionsAmmonium chlorate
Ammonium chloride
Other cationsPotassium perchlorate
Sodium perchlorate
Lithium perchlorate
Related compoundsPerchloric acid
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
 
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Ammonium perchlorate
Ammonium perchlorate
Unit cell of the crystal structure
Ammonium perchlorate 100g.jpg
Identifiers
CAS number7790-98-9 YesY
ChemSpider23041 YesY
EC number232-235-1
UN number1442
RTECS numberSC7520000
Jmol-3D imagesImage 1
Properties
Molecular formulaNH4ClO4
Molar mass117.49 g/mol
AppearanceWhite Crystalline [1]
Density1.95 g/cm3
Melting pointExothermic decomposition before melting at >200 °C[2]
Solubility in water11.56 g/100 mL (0 °C)
20.85 g/100 mL (20 °C)
57.01 g/100 mL (100 °C)
SolubilitySoluble in Methanol
partially soluble in Acetone
insoluble in Ether
Structure
Crystal structureOrthorhombic (< 513 K)
Cubic (> 513 K)
Hazards
MSDSExternal MSDS [3]
EU Index017-009-00-0
EU classificationOxidant (O)
R-phrasesR9, R44
S-phrases(S2), S14, S16, S27, S36/37
NFPA 704
NFPA 704.svg
1
2
2
OX
Autoignition temperature240 °C; 464 °F; 513 K
Related compounds
Other anionsAmmonium chlorate
Ammonium chloride
Other cationsPotassium perchlorate
Sodium perchlorate
Lithium perchlorate
Related compoundsPerchloric acid
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ammonium perchlorate is an inorganic compound with the formula NH4ClO4. It is the salt of perchloric acid and ammonia. It is a powerful oxidizer, which explains its main use in solid propellants. It has been implicated in a number of accidents, such as the PEPCON industrial disaster and the crash of South African Airways Flight 295.

Production[edit]

Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid, and is the driver behind the industrial production of perchloric acid. It also can be prepared by treatment of ammonium salts with sodium perchlorate. This process exploits the fact that the solubility of NH4ClO4 is about 10% of that for sodium perchlorate.[4]

AP crystallises into colorless rhombohedra.

Decomposition[edit]

Like most ammonium salts, ammonium perchlorate decomposes before melting. Mild heating results in the evolution of chlorine, nitrogen, oxygen, and water.

2 NH4ClO4 → Cl2 + N2 + 2 O2 + 4 H2O

The combustion of AP is quite complex and is widely studied. AP crystals decompose before melting, even though a thin liquid layer has been observed on crystal surfaces during high-pressure combustion processes.[5] Strong heating may lead to explosions. Complete reactions leave no residue. Pure crystals cannot sustain a flame below the pressure of 2 MPa.

AP is a Class 4 oxidizer (can undergo an explosive reaction) for particle sizes over 15 micrometres[6] and is classified as an explosive for particle sizes less than 15 micrometres.[7][8]

Applications[edit]

The vast majority of ammonium perchlorate is used to make solid propellants.[9] When AP is mixed with a fuel (like a powdered aluminum and/or with an elastomeric binder), it can generate self-sustained combustion at far under atmospheric pressure. It is an important oxidizer with a decades-long history of use in solid rocket propellantsspace launch (including the Space Shuttle Solid Rocket Booster), military, amateur, and hobby high-power rockets, as well as in some fireworks.

Some "breakable" epoxy adhesives contain suspensions of AP. Upon heating to 300 °C, the AP degrades the organic adhesive, breaking the cemented joint.

Toxicity[edit]

Perchlorate itself confers little acute toxicity. For example, sodium perchlorate has an LD50 of 2-4 g/kg and is eliminated rapidly after ingestion.[4] However, chronic exposure to perchlorates, even in low concentrations, has been shown to cause various thyroid problems, as it is taken up in place of iodine.

See also[edit]

References[edit]

  1. ^ http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=AE&language=en&productNumber=208507&brand=SIAL&PageToGoToURL=http%3A%2F%2Fwww.sigmaaldrich.com%2Fcatalog%2Fproduct%2Fsial%2F208507%3Flang%3Den Page 3, 9.1 (a)
  2. ^ Liu, L.; Li, F.; Tan, L.; Ming, L.; Yi, Y. (2004), "Effects of Nanometer Ni, Cu, Al and NiCu Powders on the Thermal Decomposition of Ammonium Perchlorate", Propellants, Explosives, Pyrotechnics 29: 34–38, doi:10.1002/prep.200400026 
  3. ^ https://www.sciencelab.com/msds.php?msdsId=9922929
  4. ^ a b Helmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone “Chlorine Oxides and Chlorine Oxygen Acids” in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. doi:10.1002/14356007.a06_483
  5. ^ T. L. Boggs, Deflagration Rate, Surface Structure and Subsurface Profile of Self-Deflagrating Single Crystals of Ammonium Perchlorate. AIAA Journal, 8(5), 1970, pp. 867–873.
  6. ^ NFPA 400: Hazardous Materials Code, 2010
  7. ^ NFPA 495: Explosive Materials Code, 2010
  8. ^ "Development of an Enhanced Hazard Classification System for Oxidizers Research Project, Technical Report", Safety Engineering Laboratories , Inc., The Fire Protection Research Foundation, 13 April 2006
  9. ^ "Perchlorate: Overview of Issues, Status, and Remedial Actions", ITRC, September 2005 accessed 4 July 2011