Ammonium perchlorate

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Ammonium perchlorate
Ammonium perchlorate
Unit cell of the crystal structure
Ammonium perchlorate 100g.jpg
Names
IUPAC name
Ammonium perchlorate
Other names
AP
Identifiers
  • 7790-98-9 YesY
3D model (JSmol)
  • Interactive image
ChemSpider
  • 23041 YesY
ECHA InfoCard 100.029.305
EC Number 232-235-1
PubChem CID
  • 24639
RTECS number SC7520000
UNII
  • Z3DQ8VD57X
UN number 1442
Properties
NH4ClO4
Molar mass 117.49 g/mol
Appearance White Crystalline [1]
Density 1.95 g/cm3
Melting point Exothermic decomposition before melting at >200 °C[2]
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
insoluble in Ether
Structure
Orthorhombic (< 513 K)
Cubic (> 513 K)
Hazards
Safety data sheet External MSDS [3]
GHS pictograms The exploding-bomb pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The flame-over-circle pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H201, H271, H319, H373
P210, P220, P221, P230, P240, P250, P260, P264, P280, P283, P305+351+338, P306+360, P314, P337+313, P370+378, P370+380, P371+380+375, P372, P373, P401, P501
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g., fluorine Special hazard OX: Oxidizer. E.g., potassium perchlorateNFPA 704 four-colored diamond
240 °C (464 °F; 513 K)
Related compounds
Other anions
Ammonium chlorate
Ammonium chloride
Other cations
Potassium perchlorate
Sodium perchlorate
Lithium perchlorate
Related compounds
Perchloric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYNo ?)
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. Perchlorate is a powerful oxidizer and ammonium is a good fuel. This combination explains the usefulness of this material as a rocket 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.[4]

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.[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

The primary use of ammonium perchlorate is in making solid fuel propellants.[9] When AP is mixed with a fuel (like a powdered aluminium 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

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.

References

  1. ^ MSDS. sigmaaldrich.com. 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. ^ Ammonium perchlorate MSDS. Sigma-Aldrich
  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. ^ 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. doi:10.2514/3.5780. 
  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
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