Chemical Property of Calcium nitrite
Chemical Property:
- Appearance/Colour:white crystal, or granular
- Melting Point:390oC
- Refractive Index:n20/D 1.3946
- Flash Point:110 °C
- PSA：104.98000
- Density:2.23 g/cm3
- LogP:0.50120
- 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]
- Purity/Quality:
-
99% *data from raw suppliers
Calcium nitrite solution
30 wt. % in H2O *data from reagent suppliers
Safty Information:
- Pictogram(s):
- Hazard Codes:
- Safety Statements:
23-24/25
- MSDS Files:
-
SDS file from LookChem
Total 1 MSDS from other Authors
Useful:
-
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)
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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
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Uses
Calcium nitrite has several industrial uses:
1. Calcium nitrite has high solubility, so can be used as
a solution or powder in concrete as an “anti-freeze”
during winter months as needed. Using this
antifreeze at negative temperature can promote
the hydration of minerals in cement, and the
freezing point of operative temperature can be
reduced to –25°C.
2. This salt is a steel rust inhibitor: calcium nitrite can
clean steel and protect it from rust, and can protect
steel material in concrete used to construct buildings
and structures, to extend the useful life of concrete in
buildings.
3. In concrete, Ca(NO2)2 acts as a coagulator: calcium
nitrite is free of chlorine and alkali, capable to reduce
alkali aggregation of concrete and improve its early
strength and compressive resistance. The calcium
nitrite protects steel reenforcing bars from chlorideinduced
corrosion. One advantage to calcium nitrite
is that its protection mechanism is well defined. Data
are known that show the levels of chloride to which
given levels of calcium nitrite will protect. Once corrosion initiates, the rates are lower with calcium
nitrite present. These results have been used to
produce reinforced concrete structures with
durability in excess of 50–100 years.
4. Calcium nitrite can be used as corrosion inhibitor
when added to lubricating agents.
5. Calcium nitrite can also be used in pharmaceutical,
dyes and metallurgy industries, as a mild reducing
agent. Corrosion inhibitor in lubricants, concrete.
