AMMONIUM NITRATE - (6484-52-2)

Introduction

Name: ammonium nitrate
* IUPAC
CAS Number: 6484-52-2
Chemical Formula: N2H4O3 or NH4NO3
Molar Mass: 80.04336 g
Mass Percent: N 34.997 %; H 5.0369 %; O 59.965 % 

Classification

• inorganic

Uses/Function

• "14th most produced chemical in the United States in 1995 - 8.0 megatonnes." 1

• "15th most produced chemical in the United States - 12.83 billion pounds" 2

• "The primary use of ammonium nitrate is the manufacture of fertilizers. In 2005, about 2 million metric tons (2.2 million short tons) of ammonium nitrate fertilizer was used in the United States. The compound is added to soil to provide the nitrogen that plants need to grow. It may be used by itself or in combination with another nitrogen-rich compound, urea, in a mixture known as UAN.

Ammonium nitrate is also an important component of some explosives. It provides the oxygen needed to cause some other material to catch fire and burn very rapidly, producing an explosion. One common type of explosive is made of ammonium nitrate mixed with fuel oil and called ANFO (Ammonium Nitrate Fuel Oil). When the mixture is heated, ammonium nitrate breaks down to release oxygen, which causes the rapid combustion (explosion) of the fuel oil.

Some other uses of ammonium nitrate include the following:
• In fireworks, where it provides the oxygen needed to ignite other chemicals;
• In the manufacture of nitrous oxide (N2O), commonly known as laughing gas;
• In rocket engines, where it provides the oxygen needed to burn the rocket fuel;
• In the manufacture of safety matches, where the compound supplies oxygen to substances that catch fire when the match is struck; and
• As a nutrient in commercial processing for growing yeasts and antibiotics." 3

Physical Properties

Melting Point:*
210°C †4 = 483.15 K = 410°F

Density (g/cm3):
1.72 at room temperature/pressure 4
* - 1 atm pressure
† - decomposes

Solubility

Qualitative:
slightly soluble:  4

Bonding

Thermochemistry

ΔHf° (s): -87.37 kcal/mol 5 = -365.56 kJ/mol
S° (s): 36.11 cal/(mol•K) 6 = 151.08 J/(mol•K)
ΔGf° (s): -43.98 kcal/mol 7 = -184.01 kJ/mol

Safety Information

NFPA 704 Ratings:
Health: 1 - Exposure would cause irritation with only minor residual injury.
Flammability: 0 - Will not burn.
Reactivity: 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.
Special Hazard: OX - Oxidizer.

For More Information

Sources

(1) - Chem. Eng. News, 1995, 73 (26), p 39
(2) - Reisch, Mark S.; Top 50 Chemicals Production Turned Back Up in 1987. Chemical & Engineering News, April 11, 1988, pp 30-33.
(3) - Schlager, Neil, Weisblatt, Jayne, Newton, David E., and Montney, Charles B. Chemical Compounds Vol. 1; Thomson-Gale: Detroit, MI, 2006; pp 74-76.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4-41.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(6) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(7) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.