Ammonium dichromate

Ammonium dichromate
Names
IUPAC name
Ammonium dichromate
Other names
Ammonium bichromate
Ammonium pyrochromate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.221 Edit this at Wikidata
RTECS number
  • HX7650000
UNII
UN number 1439
  • InChI=1S/2Cr.2H3N.7O/h;;2*1H3;;;;;;;/q;;;;;;;;;2*-1/p+2 checkY
    Key: JOSWYUNQBRPBDN-UHFFFAOYSA-P checkY
  • InChI=1/2Cr.2H3N.7O/h;;2*1H3;;;;;;;/q;;;;;;;;;2*-1/p+2/rCr2O7.2H3N/c3-1(4,5)9-2(6,7)8;;/h;2*1H3/q-2;;/p+2
    Key: JOSWYUNQBRPBDN-RFRSXZKWAS
  • [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O.[NH4+].[NH4+]
Properties
(NH4)2Cr2O7
Molar mass 252.07 g/mol
Appearance Orange-red crystals
Odor odorless
Density 2.115 g/cm3
Melting point 180 °C (356 °F; 453 K) decomposes
18.2 g/100 ml (0 °C)
35.6 g/100 ml (20 °C)
40 g/100 ml (25 °C)
156 g/100 ml (100 °C)
Solubility insoluble in acetone
soluble in ethanol
Structure
monoclinic
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Very toxic, explosive, oxidizing, carcinogenic, mutagenic, dangerous for the environment
GHS labelling:
GHS01: ExplosiveGHS03: OxidizingGHS05: CorrosiveGHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard[1]
H272, H301, H312, H314, H317, H330, H334, H340, H350, H360, H372, H410[1]
P201, P220, P260, P273, P280, P284[1]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 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. hydrogen peroxideSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
4
2
3
OX
190 °C (374 °F; 463 K)
Lethal dose or concentration (LD, LC):
20–250 mg/kg
Safety data sheet (SDS) ICSC 1368
Related compounds
Other cations
 Potassium dichromate
Sodium dichromate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Ammonium dichromate is an inorganic compound with the formula (NH4)2Cr2O7. In this compound, as in all chromates and dichromates, chromium is in a +6 oxidation state, commonly known as hexavalent chromium. It is a salt consisting of ammonium ions and dichromate ions.

Ammonium dichromate is sometimes known as Vesuvian Fire, because of its use in demonstrations of tabletop "volcanoes".[2] However, this demonstration has become unpopular in schools due to the compound's carcinogenic nature. It has also been used in pyrotechnics and in the early days of photography.

  1. ^ a b c Sigma-Aldrich Co., Ammonium dichromate. Retrieved on 2013-07-20.
  2. ^ "Ammonium Dichromate Volcano". Chemistry Comes Alive!. J. Chem. Educ. (dead link 29 March 2021)