Aluminum nitrate is a white, water-soluble salt of aluminum and nitric acid , usually present as the crystalline hydrate , aluminum nitrate nonhydrate, Al(NO 3 ) 3 9H 2 O.
| virtue | |
|---|---|
| chemical formula | Al (No. 3 ) 3 |
| molar mass | 212.996 g/mol (anhydrous) 375.134 g/mol (nonhydrate) |
| appearance | white crystal, solid hygroscopic |
| dirt | odorless |
| density | 1.72 g/cm3 ( nonhydrate) |
| Melting point | 66 °C (151 °F; 339) K) (anhydrous) 73.9 °C (165.0 °F; 347.0 K) (nonhydrate) |
| boiling point | 150 °C (302 °F; 423 K) (nonhydrate) decomposes |
| Solubility in water | Anhydrous: 60.0 g/100 ml (0 °C) 73.9 g/100 ml (20 °C) 160 g/100 ml (100 °C) Nonhydrate: 67.3 g/100 ml |
Preparation
Aluminum nitrate cannot be synthesized by the reaction of aluminum with concentrated nitric acid, as aluminum forms an inert layer.
Instead aluminum nitrate can be prepared by the reaction of nitric acid with aluminum(III) chloride. Nitrosyl chloride is manufactured as a by-product; It comes out of solution as a gas. More easily, the salt can be made by reacting nitric acid with aluminum hydroxide.
Aluminum nitrate can also be prepared by a metathesis reaction between aluminum sulfate and a nitrate salt with a suitable cation such as barium, strontium, calcium, silver, or lead. For example Al 2 (SO 4 ) 3 + 3 Ba(NO 3 ) 2 → 2 Al(NO 3 ) 3 + 3 BaSO 4 .
Use
Aluminum nitrate is a strong oxidising agent. It is used in tanning leather, antiperspirants, corrosion inhibitors, extraction of uranium, petroleum refining, and as a nitrating agent.
Nonhydrate and other hydrated aluminum nitrates have many applications. These salts are used to produce papers for the preparation of insulating alumina, in cathode ray tube heating elements and on, transformer core laminates. Hydrated salts are also used for the extraction of actinide elements. [3]
It is used in the laboratory and in the classroom such as in the reactionAl(NO 3 ) 3 + 3 NaOH → Al (OH) 3 + 3 NaNO 3
However, it is encountered much less frequently than aluminum chloride and aluminum sulfate.
