Ammonium iron(II) sulfate
 |
This article is a stub. Please help Sciencemadness Wiki by expanding it, adding pictures, and improving existing text.
|
_sulfate_hexahydrate_sample.jpg) Sample of Mohr's salt and original bottle
| |
| Names | |
|---|---|
| IUPAC name
Ammonium iron(II) sulfate
| |
| Other names
Ammonium iron sulfate
Diammonium iron(II) sulfate Ferrous ammonium sulfate Mohr's salt | |
| Properties | |
| FeH8N2O8S2 (NH4)2Fe(SO4)2 (anhydrous) (NH4)2Fe(SO4)2·6 H2O (hexahydrate) | |
| Molar mass | 284.05 g/mol (anhydrous) 392.13 g/mol (hexahydrate) |
| Appearance | Light blue or green solid |
| Odor | Odorless |
| Density | 1.86 g/cm3 (20 °C) |
| Melting point | 100–110 °C (212–230 °F; 373–383 K) (decomposes) |
| Boiling point | Decomposes |
| hexahydrate 26.9 g/100 ml | |
| Solubility | Insoluble in esters, ethers, halocarbons, hydrocarbons |
| Vapor pressure | ~0 mmHg |
| Hazards | |
| Safety data sheet | Sigma-Aldrich (hexahydrate) |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Ammonium sulfate Iron(II) sulfate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Ammonium iron(II) sulfate, more commonly referred to as Mohr's salt, is an inorganic chemical compound with the formula (NH4)2Fe(SO4)2·6 H2O as hexahydrate. Containing two different cations, Fe2+ and NH4+, it is classified as a double salt of ferrous sulfate and ammonium sulfate.
Contents
Properties
Chemical
Addition of a base like sodium hydroxide will precipitate iron(II) hydroxide, releasing ammonia gas.
Unlike other Fe2+ compounds, Mohr's salt resists air oxidation much better, which makes it useful in analytical chemistry.
Physical
Ammonium iron (II) sulphate is a light blue or greenish solid, soluble in water.
Availability
Ammonium iron(II) sulphate is sold by chemical suppliers. Can also be bought online.
Preparation
Mohr's salt is prepared by dissolving an equimolar mixture of iron(II) sulfate heptahydrate and ammonium sulfate in water, with a bit of sulfuric acid. The solution is cooled to crystallize the compound, which is removed from the solution, washed and dried.
Projects
- Grow crystals
- Source of ferrous ions in chemical reactions
Handling
Safety
Ammonium iron(II) sulphate has low toxicity, though contact with strong bases will release irritant ammonia fumes.
Storage
Mohr's salt should be kept in closed bottles.
Disposal
No special disposal is required. Mohr's salt can be used as nitrogen, iron and sulfur fertilizer.
