Chemical elements
  Calcium
    Isotopes
    Energy
    Preparation
    Physical Properties
    Chemical Properties
      Calcium Hydride
      Calcium Subfluoride
      Calcium Fluoride
      Calcium Subchloride
      Calcium Chloride
      Calcium Bromide
      Calcium Subiodide
      Calcium Iodide
      Calcium Periodides
      Calcium Halides
      Calcium Perhalides
      Calcium Oxychloride
      Calcium Hypochlorite
      Bleaching Powder
      Calcium Chlorite
      Calcium Chlorate
      Calcium Perchlorate
      Calcium Oxybromide
      Calcium Hypobromite
      Brome Bleaching Powder
      Calcium Bromate
      Calcium Oxyiodide
      Calcium Hypoiodite
      Iodine Bleaching Powder
      Calcium Iodate
      Calcium Periodate
      Calcium Manganites
      Calcium Manganate
      Calcium Permanganate
      Calcium Oxide
      Caustic lime
      Calcium Suboxide
      Calcium Hydroxide
      Lime
      Calcium Peroxide
      Calcium Peroxyhydrates
      Calcium Tetroxide
      Calcium Monosulphide
      Calcium Hydrosulphide
      Calcium Polysulphides
      Calcium Hydroxyhydrosulphide
      Calcium Oxysulphides
      Calcium Thiosulphate
      Calcium Hyposulphite
      Calcium Sulphite
      Calcium Bisulphite
      Calcium Sulphite
      Calcium Dithionate
      Calcium Trithionate
      Calcium Sulphate
      Acid Calcium Sulphates
      Calcium Pyrosulphate
      Calcium Selenide
      Calcium Selenite
      Calcium Selenate
      Calcium Telluride
      Calcium Tellurite
      Calcium Tellurate
      Calcium Chromite
      Calcium Chromate
      Calcium Dichromate
      Calcium Tetrachromate
      Basic Calcium Chromate
      Calcium Chlorochromate
      Calcium Molybdate
      Calcium Tungstate
      Calcium Uranate
      Calcium Peruranate
      Calcium Nitride
      Calcium Azide
      Calcium Hexammoniate
      Calcium Ammonium
      Calcium Amide
      Calcium Imide
      Calcium Hydroxylamite
      Calcium Imidosulphonate
      Calcium Hyponitrite
      Calcium Nitrohydroxylaminate
      Calcium Nitrite
      Calcium Nitrate
      Basic Calcium Nitrates
      Calcium Phosphide
      Calcium Dihydrohypophosphite
      Calcium Hydrophosphite
      Neutral Calcium Phosphite
      Calcium Dihydrophosphite
      Acid Calcium Phosphite
      Neutral Calcium Hypophosphate
      Acid Calcium Hypophosphate
      Calcium Orthophosphates
      Calcium Pyro- Meta-phosphates
      Calcium Ultraphosphates
      Calcium Selenophosphate
      Basic Calcium Phosphates
      Phosphatic Fertilisers
      Calcium Arsenide
      Calcium Arsenites
      Calcium Arsenates
      Calcium Pyroarsenate
      Calcium Thioarsenites
      Calcium Thio-oxyarsenate
      Calcium Antimonide
      Calcium Antimonate
      Calcium Orthovanadate
      Calcium Pyrovanadate
      Calcium Metavanadate
      Calcium Pervanadate
      Calcium Pyro- Meta- niobates
      Calcium Pyro- Meta-tantalate
      Calcium Potassium Pertantalate
      Calcium Carbide
      Calcium Formate
      Calcium Acetate
      Calcium Oxalate
      Calcium Carbonate
      Calcium Bicarbonate
      Calcium Trithiocarbonate
      Calcium Perthiocarbonate
      Calcium Cyanide
      Calcium Oxycyanide
      Calcium Cyanamide
      Calcium Cyanate
      Calcium Cyanurate
      Calcium Thiocyanate
      Calcium Silicide
      Calcium Monosilicide
      Calcium Silicalcyanide
      Monocalcium Silicate
      Calcium Meta-silicate
      Calcium Orthosilicate
      Dicalcium Silicate
      Tricalcium Silicate
      Acid Calcium Silicate
      Calcium Fluosilicate
      Calcium Aluminates
      Monocalcium Aluminate
      Tricalcium Aluminate
      Pentacalcium Aluminate
      Calcium Stannate
      Calcium Chlorostannate
      Calcium Silicostannate
      Calcium Orthoplumbate
      Calcium Metaplumbate
      Acid Calcium Plumbate
      Calcium Metatitanate
      Calcium Fluotitanate
      Calcium Silicotitanate
      Calcium Zirconate
      Calcium Silicozirconate
      Calcium Boride
      Calcium Borates
      Calcium Silicoborate
      Calcium Borostannate
      Calcium Perborate
      Calcium Ferrate
    Glass
    Cement
    PDB 158d-1ajq
    PDB 1ak9-1ayk
    PDB 1ayo-1bg7
    PDB 1bg9-1byh
    PDB 1byn-1c8q
    PDB 1c8t-1cq1
    PDB 1cq9-1daq
    PDB 1dav-1dva
    PDB 1dvi-1el1
    PDB 1ela-1f4n
    PDB 1f4o-1fkq
    PDB 1fkv-1fzd
    PDB 1fze-1g9i
    PDB 1g9j-1gr3
    PDB 1gsl-1h5h
    PDB 1h5i-1hn4
    PDB 1hny-1i9z
    PDB 1ia6-1iyi
    PDB 1iz7-1jc2
    PDB 1jc9-1jui
    PDB 1jv2-1kck
    PDB 1kcl-1kvx
    PDB 1kvy-1led
    PDB 1lem-1lqd
    PDB 1lqe-1may
    PDB 1mbq-1mxe
    PDB 1mxg-1nfy
    PDB 1ng0-1nwg
    PDB 1nwk-1o3g
    PDB 1o3h-1om7
    PDB 1om8-1p7v
    PDB 1p7w-1pva
    PDB 1pvb-1qdo
    PDB 1qdt-1qq9
    PDB 1qqj-1rin
    PDB 1rio-1s10
    PDB 1s18-1scv
    PDB 1sdd-1su4
    PDB 1sub-1tf4
    PDB 1tf8-1top
    PDB 1tpa-1ujb
    PDB 1ujc-1uyy
    PDB 1uyz-1v73
    PDB 1v7v-1w2k
    PDB 1w2m-1wua
    PDB 1wun-1xkv
    PDB 1xmf-1y3x
    PDB 1y3y-1yqr
    PDB 1yr5-1zde
    PDB 1zdp-2a3x
    PDB 2a3y-2arb
    PDB 2are-2bd2
    PDB 2bd3-2bu4
    PDB 2bue-2c6g
    PDB 2c6p-2cy6
    PDB 2cyf-2dso
    PDB 2dtw-2eab
    PDB 2eac-2fe1
    PDB 2ff1-2fwn
    PDB 2fws-2gjp
    PDB 2gjr-2hd9
    PDB 2hes-2i6o
    PDB 2i7a-2ivz
    PDB 2iwa-2j7g
    PDB 2j7h-2jke
    PDB 2jkh-2kuh
    PDB 2kxv-2o1k
    PDB 2o39-2ovz
    PDB 2ow0-2pf2
    PDB 2pfj-2pyz
    PDB 2pz0-2qu1
    PDB 2qua-2re1
    PDB 2rex-2tmv
    PDB 2tn4-2vcb
    PDB 2vcc-2vqy
    PDB 2vr0-2w3i
    PDB 2w3j-2wlj
    PDB 2wm4-2wzs
    PDB 2x0g-2xmr
    PDB 2xn5-2z2z
    PDB 2z30-2zn9
    PDB 2zni-3a51
    PDB 3a5l-3ahw
    PDB 3ai7-3bcf
    PDB 3bdc-3bx1
    PDB 3bxi-3ch2
    PDB 3chj-3d34
    PDB 3d3i-3djl
    PDB 3dng-3e4q
    PDB 3e5s-3eqf
    PDB 3eqg-3faq
    PDB 3faw-3fou
    PDB 3foz-3gci
    PDB 3gcj-3gwz
    PDB 3gxo-3hjr
    PDB 3hkr-3i4i
    PDB 3i4p-3io6
    PDB 3ior-3k5m
    PDB 3k5s-3kqa
    PDB 3kqf-3lei
    PDB 3lek-3lum
    PDB 3lun-3mip
    PDB 3mis-3n7b
    PDB 3n7x-3nvn
    PDB 3nx7-3owf
    PDB 3ox5-3prq
    PDB 3prr-3sg5
    PDB 3sg6-3u39
    PDB 3u43-3vpp
    PDB 3zqx-4awy
    PDB 4awz-4dtu
    PDB 4dtx-4eoa
    PDB 4epz-5apr
    PDB 5bca-8tln
    PDB 966c-9rnt

Calcium Nitrate, Ca(NO3)2






Calcium Nitrate, Ca(NO3)2, does not occur as a mineral form but is often found in natural waters and in the soil as a product of putrefaction and bacterial nitrification. The tetrahydrate forms part of the efflorescence often seen on damp walls, especially on the walls of stables.

It is prepared by the neutralisation of calcium hydroxide or calcium carbonate by nitric acid. The anhydrous salt, which may be obtained by drying the hydrated salt at 170° C., is very deliquescent. The melting-point is 499° C., at which temperature decomposition has already set in to a slight extent. The eutectic mixture of potassium and calcium nitrates, containing 25.36 per cent, of the latter, melts at 251° C.

The heat of formation of anhydrous calcium nitrate from its elements is 216.7 Cal., and the heat of solution 3.95 Cal. The density is 2.240 – 2.504. The anhydrous salt crystallises from a hot aqueous or nitric acid solution in microscopic regular octahedra.

Calcium nitrate is very readily soluble in water and tends to form supersaturated solutions. The properties of aqueous calcium nitrate solutions have been extensively investigated with reference to their boiling-points, freezing-points, vapour pressures, densities, refractive indices, viscosities, electrical conductivities, and degree of dissociation. The boiling-point of the saturated solution at 760 mm. pressure is 151° C., and the solution contains 79 per cent, of calcium nitrate.


The Hydrates of Calcium Nitrate

Calcium nitrate forms several hydrates. The tetrahydrate crystallises from solution at ordinary temperatures in long monoclinic needles. The density is 1.82. The heat of hydration of calcium nitrate is 11.200 Cal., and the heat of solution of the tetrahydrate –7.250 Cal.

Calcium nitrate - water equilibria
Equilibria in the system, calcium nitrate: water
From vapour pressure measurements Lescoeur concluded that a di- and tri-hydrate probably exist. More recent work has not only confirmed this, but has revealed the existence of a second and unstable modification of the tetrahydrate. The nature of the solid phases in contact with saturated solutions of calcium nitrate at different temperatures is indicated by the curves in Fig.

The cryohydric temperature indicated by point A is -28.7° C. at a concentration of 42.9 per cent, of anhydrous salt.

The melting-point of the stable α-tetrahydrate (point B) is 42.7° C., and of the β-form (point B'), 39.6° C.

The trihydrate, the stable hydrate between C and E, which forms flattened prismatic crystals apparently belonging to the triclinic system, melts at 51.1° C. (point D).

The dihydrate in smaller prismatic crystals has no true melting- point, as can be seen from the diagram where the range of existence is line EF lying between the temperatures 48.4° and 51.3° C.

As the line FG shows, there is only a very slight increase in the solubility of the anhydrous salt with rise of temperature.

A hexahydrate, Ca(NO3)2.6H2O, of melting-point 26.4° C., is mentioned by Tilden, but there does not appear to be any confirmatory evidence.

Calcium nitrate, known as " air-saltpetre," is obtained technically in the fixation of atmospheric nitrogen by the arc process, the nitrous gases being absorbed by calcium oxide or calcium carbonate. It is as effective a fertiliser as sodium nitrate, but it has not appeared to any great extent in the English country markets. The difficulties caused by its hygroscopic nature have to some extent been overcome.

The preparation of calcium nitrate on a commercial scale by the bacterial oxidation of calcium cyanamide, or of ammonium compounds in the presence of calcium carbonate, has also been suggested.

A patent has been taken out for neutralising nitric acid with a mixture of rock phosphate and limestone. A hard dry mass of considerable fertilising value is said to be obtained.

Addition Compounds of Calcium Nitrate

Calcium nitrate solutions absorb ammonia more readily than does pure water, evidently as the result of the formation of a complex cation Ca(NH3)n.

Calcium nitrate is very soluble in ethyl alcohol and forms an alcoholate, Ca(NO3)2.2C2H5OH. It also dissolves readily in methyl, propyl, isobutyl, and amyl alcohols, and in acetone, but not in ether and paracetaldehyde.
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