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Ammonium perchlorate

Names
IUPAC name Ammonium perchlorate
Other names AP
Identifiers
CAS Number	7790-98-9
3D model (JSmol)	Interactive image
ChemSpider	23041
ECHA InfoCard	100.029.305
EC Number	232-235-1
PubChem CID	24639
RTECS number	SC7520000
UNII	Z3DQ8VD57X
UN number	1442
CompTox Dashboard (EPA)	DTXSID4024515
InChI InChI=1S/ClHO4.H3N/c2-1(3,4)5;/h(H,2,3,4,5);1H3Key: HHEFNVCDPLQQTP-UHFFFAOYSA-N InChI=1/ClHO4.H3N/c2-1(3,4)5;/h(H,2,3,4,5);1H3Key: HHEFNVCDPLQQTP-UHFFFAOYAD
SMILES Cl(=O)(=O)=O.
Properties
Chemical formula	NH4ClO4
Molar mass	117.49 g/mol
Appearance	White crystalline
Density	1.95 g/cm
Melting point	Exothermic decomposition before melting at >200 °C
Solubility in water	11.56 g/100 mL (0 °C) 20.85 g/100 mL (20 °C) 57.01 g/100 mL (100 °C)
Solubility	Soluble in methanol Partially soluble in acetone, ethanol Insoluble in diethyl ether
Structure
Crystal structure	Orthorhombic (<240 °C) Cubic (>240 °C)
Thermochemistry
Std enthalpy of formation (ΔfH298)	-295.77 kJ/mol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H201, H271, H319, H373
Precautionary statements	P210, P220, P221, P230, P240, P250, P260, P264, P280, P283, P305+P351+P338, P306+P360, P314, P337+P313, P370+P378, P370+P380, P371+P380+P375, P372, P373, P401, P501
NFPA 704 (fire diamond)	1 0 2OX
Safety data sheet (SDS)	External MSDS
Related compounds
Other anions	Ammonium chlorate Ammonium chloride
Other cations	Potassium perchlorate Sodium perchlorate Lithium perchlorate
Related compounds	Perchloric acid Ammonium perbromate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

Ammonium perchlorate ("AP") is an inorganic compound with the formula NH₄ClO₄. It is a colorless or white solid that is soluble in water. It is a powerful oxidizer. Combined with a fuel, it can be used as a rocket propellant called ammonium perchlorate composite propellant. Its instability has involved it in a number of accidents, such as the PEPCON disaster.

Production

Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate. This process exploits the relatively low solubility of NH₄ClO₄, which is about 10% of that for sodium perchlorate.

AP crystallises as colorless rhombohedra.

Decomposition

Like most ammonium salts, ammonium perchlorate decomposes before melting. Mild heating results in production of hydrogen chloride, nitrogen, oxygen, and water.

4 NH₄ClO₄ → 4 HCl + 2 N₂ + 5 O₂ + 6 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. 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 and is classified as an explosive for particle sizes less than 15 micrometres.

Applications

During World War I England and France used mixtures featuring ammonium perchlorate (such as "balstine") as a substitute high explosive.

The primary use of ammonium perchlorate is in making solid rocket propellants. When AP is mixed with a fuel (like a powdered aluminium and/or with an elastomeric binder), it can generate self-sustained combustion at pressures far below atmospheric pressure. It is an important oxidizer with a decades-long history of use in solid rocket propellants – space 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

Perchlorate itself confers little acute toxicity. For example, sodium perchlorate has an LD₅₀ of 2–4g/kg and is eliminated rapidly after ingestion. 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.

References

1. MSDS. sigmaaldrich.com.
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. John Rumble (18 June 2018). CRC Handbook of Chemistry and Physics (99th ed.). CRC Press. pp. 4–41. ISBN 978-1138561632.
4. Chase, M. W. (11 February 1998). "NIST-JANAF Themochemical Tables, Fourth Edition". pp. 1–1951.
5. Ammonium perchlorate MSDS. Sigma-Aldrich
6. ^ 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
7. Boggs, T. L. (1970). "Deflagration Rate, Surface Structure and Subsurface Profile of Self-Deflagrating Single Crystals of Ammonium Perchlorate". AIAA Journal. 8 (5): 867–873. Bibcode:1970AIAAJ...8..867B. doi:10.2514/3.5780.
8. NFPA 400: Hazardous Materials Code, 2010
9. NFPA 495: Explosive Materials Code, 2010
10. "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
11. "Perchlorate: Overview of Issues, Status, and Remedial Actions" Archived 15 March 2012 at the Wayback Machine, ITRC, September 2005

Further reading

• Schmidt, Eckart W. (2022). "Perchlorate Oxidizers". Encyclopedia of Oxidizers. De Gruyter. pp. 3383–3880. doi:10.1515/9783110750294-028. ISBN 978-3-11-075029-4.

• Ammonium compounds
• Perchlorates
• Pyrotechnic oxidizers
• Rocket oxidizers
• Oxidizing agents
• Explosive chemicals