Ammonium nitrate (phase IV) | SSHADE

Processing math: 63%

Solid phase

Official name: Ammonium nitrate (phase IV)

Name and identifiers

Secondary names: Nitrate of ammonia; Nitric acid ammonium salt (1:1); Nitric acid ammonium salt; azanium;nitrate; IV-NH4NO3; gwihabaite; nitrammite; (NH4+)NO3-; H4N2O3
CAS number: 6484-52-2

Family: ionic solid
Class: normal salt
Compound type: nitrate

Chemical composition

Formula: $NH_4^+ \cdot NO_3^-$
Chemical formula: (NH4)NO3
Elemental formula: (N+)2 H4 O (O-)2
Isotope mixture type: terrestrial abundance

4.0

	Formula	Name	Family	Number min-max	Mole fraction	Isotope mole fraction	State	Relevance
	$NH_4^+$	Ammonium ion	molecule	1	0.5	1	constituent cation	main
	$(NO_3)^-$	Nitrate anion	chemical function	1	0.5	1	constituent anion	main

Chemical functions and bonds

Chemical functions

	Function	Number
	$H_4 >\mid N^+$	1
	$(NO_3)^-$	1

Chemical bonds

	Bond	Number
	$>\mid N^+ \cdot O^{-}-$	1
	$\geq N^+-H$	4
	$\dddot - \dddot - N^+ \dddot - O^{-2/3}$	3

Class: normal salts (07)
Type: simple normal salts (07.01)
Group: nitrate (07.01.06)

Associated phases

Equivalent mineral: Gwihabaite

Crystallography

Phase name: Ammonium nitrate-IV [or IV-(NH4)NO3]
Phase type: crystalline
Crystal system: orthorhombic
Crystal class: dipyramidal
Crystal class symbol: mmm (D2h)
Crystal spacegroup: Pmmm

Physical properties

Molar mass: 80.043 $g/mol$
Density: 1.725 $g/cm^3$

Thermodynamical properties

State NTP

solid

Phase transitions

Phase transition type	Other phases	Temperature - Pressure
solid-liquid	liquid (start decomposes)	169.6 °C (442.8K) at 1 atm
solid-solid	V-NH4NO3	below -17°C (256.2K)
solid-solid	III-NH4NO3	above 32.2°C (305.4K)

Phase transitions comments

boiling point: ~210°C (483K) decomposes

Optical properties

Refringence type: biaxial
Refraction index $n_{\alpha}$: 1.611 at 587.6 nm
Pure color: colorless
Color: colorless, white, gray, brown
Diaphaneity: transparent to translucent

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