Calcium nitrate

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Calcium nitrate
Calcium nitrate tetrahydrate.jpg
Calcium nitrate in its hydrated form.
Names
IUPAC name
Calcium nitrate
Other names
Calcium dinitrate
Kalksalpeter
Lime nitrate
Nitrocalcite
Norwegian saltpeter
Properties
Ca(NO3)2
Molar mass 164.088 g/mol (anhydrous)
236.15 g/mol (tetrahydrate)
Appearance White hygroscopic solid
Density 2.504 g/cm3 (anhydrous)
1.896 g/cm3 (tetrahydrate)
Melting point anhydrous
561 °C (1,042 °F; 834 K)
tetrahydrate
42.7 °C (109 °F; 316 K)
Boiling point anhydrous
Decomposes
tetrahydrate
132 °C (270 °F; 405 K)
anhydrous
121.2 g/100 ml (20 °C)
271 g/100 ml (40 °C)
tetrahydrate
105 g/100 ml (0 °C)
129 g/100 ml (20 °C)
363 g/100 ml (100 °C)
Solubility Soluble in ammonia
Almost insoluble in nitric acid
Solubility in ethanol 51.4 g/100 g (20 °C)
62.9 g/100 g (40 °C)[1]
Solubility in methanol 134 g/100 g (10 °C)
144 g/100 g (40 °C)
158 g/100 g (60 °C)
Solubility in acetone 1.68 g/100 g (20 °C)
Acidity (pKa) 6.0
Hazards
Safety data sheet Sigma-Aldrich (tetrahydrate)
Lethal dose or concentration (LD, LC):
302 mg/kg (rat, oral)
Related compounds
Related compounds
Magnesium nitrate
Strontium nitrate
Barium nitrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Calcium nitrate, also called Norwegian saltpeter (Norgessalpeter), is the inorganic calcium compound with the formula Ca(NO3)2, commonly used as a fertilizer.

Properties

Chemical

Calcium nitrate is a source of both calcium and nitrate ions in reactions. Because of its hygroscopicity, it is unsuitable for use as an oxidizer in energetic mixtures; however, due to the insolubility of many calcium salts, the nitrate ion in calcium nitrate can easily be used to prepare other more useful nitrates as well as other calcium compounds. Examples of this include the addition of sodium carbonate to precipitate calcium carbonate and leave sodium nitrate in solution, or the addition of potassium sulfate to generate potassium nitrate in solution, precipitating calcium sulfate. Virtually any nitrate compound can be produced by addition of a sulfate or carbonate solution in this manner.

Physical

Calcium nitrate is a white, hygroscopic solid. It presents itself as a tetrahydrate. Calcium nitrate is extremely soluble in water. The dissolution of calcium nitrate tetrahydrate in water is highly endothermic, making it useful in cooling baths. It is also soluble in alcohol and acetone, but insoluble in concen. nitric acid.

Availability

Calcium nitrate can be bought as a fertilizer, often for hydroponics. It is fairly pure, unlike ammonium nitrate which usually contains calcium sulfate to reduce its explosive hazard. However it can also be found together with ammonium nitrate, and that fertilizer is known as calcium ammonium nitrate.

Preparation

Calcium nitrate can be prepared from the reaction of calcium carbonate and nitric acid. It can also be prepared by reacting calcium hydroxide with ammonium nitrate.

Projects

Handling

Safety

Because of its hygroscopicity, it cannot sustain an energetic mixture like other nitrates, such as potassium nitrate can, making it useful as a safe nitrate ion source. Skin contact with the anhydrous compound should be avoided as it can be irritating.

Storage

Calcium nitrate hydrate should be stored in closed bottles, in a place with low moisture. The anhydrous form should be stored in sealed bottles, as it is hygroscopic.

Disposal

Calcium nitrate without toxic impurities can be safely dumped in the environment, as it has low toxicity and it is a nitrogen source for plants. Avoid dumping large amounts though.

References

  1. http://chemister.ru/Database/properties-en.php?dbid=1&id=558

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