Iron(III) nitrate

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Iron(III) nitrate
Names
IUPAC name
Iron(III) nitrate
Other names
Ferric nitrate
Iron trinitrate
Properties
FeN3O9
Fe(NO3)3
Molar mass 403.999 g/mol (nonahydrate)
241.86 g/mol (anhydrous)
Appearance Pale violet hygroscopic crystals
Odor Odorless
Density 1.68 g/cm3 (20 °C) (hexahydrate)
1.6429 g/cm3 (20 °C) (nonahydrate)
Melting point 47.2 °C (117.0 °F; 320.3 K) (Nonahydrate)
Boiling point 125 °C (257 °F; 398 K) (nonahydrate)
150 g/100 ml (hexahydrate)
Solubility Soluble in acetone, ethanol, methanol
Hazards
Safety data sheet Sigma-Aldrich (nonahydrate)
Lethal dose or concentration (LD, LC):
3,250 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Iron(III) nitrate, also called ferric nitrate, is the chemical compound with the formula Fe(NO3)3. Since it is deliquescent, it is commonly found in its nonahydrate form Fe(NO3)3·9H2O, in which it forms pale violet crystals. When dissolved, it forms yellow solution due to hydrolysis, as such, small amounts of nitric acid are often added to inhibit hydrolysis.

Properties

Chemical

Ferric nitrate is the catalyst of choice for the synthesis of sodium amide from a solution of sodium metal in liq. ammonia.

Just like in the case of aluminium nitrate, another salt with three nitrate anions, iron(III) nitrate is rarely chosen as oxidizer in mixtures, due to its hygroscopicity.

Physical

Ferric nitrate is a pale-violet hygroscopic solid, very soluble in water.

Availability

Iron(III) nitrate is sold by chemical suppliers.

Preparation

Iron(III) nitrate can be prepared by treating iron metal powder or shavings with a slight excess of diluted nitric acid.

Fe + 4 HNO3 → Fe(NO3)3 + NO + 2 H2O.

The solid product is obtained by gently evaporating the water and then dried in an desiccator.

To obtain extremely pure and anhydrous ferric nitrate, the hydrated solid form is gently heated in a stream of nitrogen dioxide, to convert the water into nitric acid, then dried in a vacuum with a cold trap to remove all the HNO3.

Projects

  • Source of nitrate
  • Make sodium amide
  • Make nitric acid
  • Make Clayfen reagent (ferric nitrate on montmorillonite)
  • Etch silver and silver alloys

Handling

Safety

Iron(III) nitrate is irritant and when dry a powerful oxidizer. Handle it with proper protection.

Storage

In closed air-tight bottles.

Disposal

Can be diluted and poured in the ground, as it's a good source of nitrogen and iron for plants.

References

Relevant Sciencemadness threads