Calcium nitrite represented by the chemical formula Ca(NO₂)₂ or CaN₂O₄ that bears the IUPAC name calcium dinitride ^[1] is an odorless white or light yellowish deliquescent powder that is very soluble in water and slightly in alcohol ^{[4, 5]}. It is a calcium salt and an ionic compound ^[1]. It should be protected from heat as temperatures higher than 220°C would lead to its reduction and decomposition into nitrous oxide ^[5].

Calcium Nitrite Identification
CAS Number	13780-06-8 [1]
PubChem CID	159695 [1]
ChemSpider ID	140414 [2]
EC Number	237-424-2 [1]

How to Make It

Calcium nitrite can be prepared in solution by reacting silver nitrite with calcium chloride ^[8].

2AgNO₂ + CaCl₂ = 2AgCl + Ca(NO₂)₂

Properties and Characteristics of Calcium Nitrite

General Properties
Molar mass/molecular weight		132.088 g/mol [1]
Physical Properties
Color/appearance		White to yellow crystals [3]
Melting point/freezing point		390°C, 734°F [5]
Boiling point		Unknown [3]
Density		2.265 g cm-3 [3]
State of matter at room temperature (normal phase)		Solid [3]
Chemical Properties
Solubility in water		43 g/100g (at 18.5oC) [4]
pH		9.0 – 11.0 (basic) [6]
Atomic Properties
Crystal structure	Hexagonal [4]

Prominent Reactions

Calcium nitrite reacts with oxygen to form calcium nitrate ^[9].

Ca(NO₂)₂ + O₂ = Ca(NO₃)₂

Calcium Nitrite Uses

1. As a corrosion inhibitor in concrete, lubricants ^[3].
2. Its high solubility facilitates its application as antifreeze either in powder or solution form. ^[5].
3. To prepare calcium nitrate, an important component of many fertilizers ^[7].
4. To safeguard metals from salt corrosion ^[7].

Is It Dangerous

The compound is poisonous and should not be combined with inflammable, organic articles. Under fire conditions, it emits hazardous toxic fumes. Ingestion, inhalation, eye and skin contact with it should be avoided ^{[3, 6]}.

Calcium Nitrite Price

94% Ca(NO₂)₂ costs around $500-750 per metric ton. The price may vary with suppliers ^[10].

References
1. Calcium Nitrite – Pubchem.ncbi.nlm.nih.gov
2. MFCD00049399 – Chemspider.com
3. Calcium Nitrite (13780-06-8) – Chemicalbook.com
4. Calcium Nitrite – Chemicalbook.com
5. Calcium Nitrite – Wikiwand.com
6. Calcium Nitrite Solution – Kemele.com
7. Calcium Nitrite Fertilizer Uses – Homeguides.sfgate.com
8. Calcium Nitrite, Ca(NO₂)₂ – Calcium.atomistry.com
9. Calcium Nitrite – Sciencedirect.com
10. Calcium Nitrite Price – Alibaba.com