| Identification | More | [Name]
Calcium nitrite | [CAS]
13780-06-8 | [Synonyms]
CALCIUM NITRITE
Nitrousacid,calciumsalt
CALCIUM NITRITE, 30 WT. % SOLUTION IN WA TER
CalciumNitriteCa(NO3)2*4H2O
calcium nitrite solution
CALCIUM NITRITE ANHYDROUS
Calcium dinitrite
Daraset | [EINECS(EC#)]
237-424-2 | [Molecular Formula]
CaN2O4 | [MDL Number]
MFCD00049399 | [Molecular Weight]
132.09 | [MOL File]
13780-06-8.mol |
| Chemical Properties | Back Directory | [Melting point ]
390 °C | [density ]
2.23 | [refractive index ]
n20/D 1.3946
| [Fp ]
110 °C | [solubility ]
slightly soluble in ethanol | [form ]
white-yellow hexagonal crystals | [color ]
white-yellow hexagonal, hexane crystals, crystalline;
hygroscopic | [Water Solubility ]
slightly soluble alcohol [MER06]; g/100g solution H2O: 38.3 (0°C), 43.0 (18.5°C), 71.2 (91°C); solid phase Ca(NO2)2 · 4H2O (0°C, 18.5°C), Ca(NO2)2 ·2H2O (91°C) [KRU93] | [Merck ]
13,1688 | [LogP]
-2.52 at 20℃ | [CAS DataBase Reference]
13780-06-8(CAS DataBase Reference) | [EPA Substance Registry System]
13780-06-8(EPA Substance) |
| Hazard Information | Back Directory | [Chemical Properties]
white or yellowish deliquescent, hexagonal crystal(s); prepared from nitric oxide and a mixture consisting of calcium ferrate and calcium nitrate; used to inhibit corrosion in lubricants and concrete [MER06] | [Uses]
Corrosion inhibitor in lubricants, concrete. | [Description]
Calcium nitrite has the formula of Ca(NO2)2 and the
molecular weight of 132.0894 g/mol. It can be made by
the usual double decomposition reaction of sodium
nitrite and CaCl2. It forms a tetrahydrate that is isomorphous
with the strontium and barium salts:
2Na2NO2 (aq) + CaCl2 ? Ca(NO2)2 (aq) + 4NaCl (aq)
| [Physical properties]
Calcium nitrite, Ca(NO2)2, has the CAS number of
13780-06-8 and occurs as yellow-white crystals. It is
very hygroscopic. Its density is 2.23 g/cm3 and it
decomposes at 392°C to form nitrogen oxides and
CaO. It is slightly soluble in alcohol. Ca(NO2)2·4H2O
loses two waters of hydration at about 80°C and one
at 105°C to form the monohydrate. It loses the other at
about 155°C. The anhydrate, if further heated, is
unstable and oxidizes to the nitrate in air above 220°C:
Ca(NO2)2 + O2 + heat?Ca(NO3)2 | [Preparation]
Industrially, calcium nitrite is manufactured by reacting
“NOX” gas with “l(fā)ime”:
Ca(OH)2 + NO +NO2?Ca(NO2)2 +H2O
By carefully controlling calciumnitrite conditions, the
selectivity on converted lime, on a molar basis, is over
95% pure. It is soluble in water (98.2 g/100 ml at
20 °C) and the solution must be evaporated at low
temperature to obtain the tetrahydrate. If heated with
NO2 gas, it also form the nitrate:
Ca(NO2)2 + NO2?Ca(NO3)2 + NO
Anhydrous calcium nitrite is unstable and slowly
oxidizes in air to form the nitrate. It is also soluble in
alcohol at 0.97 g/100 ml at 20 °C. | [Purification Methods]
Crystallise it from hot water (1.4mL/g) by adding ethanol and cooling to give the hydrate. It is deliquescent. [Ray & Ogg J Am Chem Soc 79 265 1957.] | [General Description]
Calcium nitrite solution (Ca(NO2)2) is widely utilized as a corrosion inhibitor. It protects the metal surface against chloride attack and increases the threshold level and improves the overall life of the concrete. Ca(NO2)2 does not change the mechanical properties of the cement. | [Flammability and Explosibility]
Notclassified |
| Safety Data | Back Directory | [Safety Statements ]
S23:Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer) .
S24/25:Avoid contact with skin and eyes . | [WGK Germany ]
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