Molecular Structure:

Molecular Formula: Cl₂Co
Molecular Weight: 129.8392
IUPAC Name: Dichlorocobalt
Synonyms of Cobaltous chloride (CAS NO.7646-79-9):  CCRIS 4224 ; Cobalt chloride (CoCl2) ; Cobalt muriate ; Cobalt(II) chloride ; Cobaltous dichloride ; Dichlorocobalt ; EINECS 231-589-4 ; HSDB 1000 ; Kobalt chlorid (German) ; NSC 51149 ; UNII-EVS87XF13W
CAS NO: 7646-79-9
Classification Code: Antimutagenic Agents ; Protective Agents
Melting point: 724 °C 
Enthalpy of Vaporization: 16.15 kJ/mol
Vapour Pressure: 33900 mmHg at 25°C 
Boiling Point: 1049 °C
Density: 3.35
Vapor pressure: 40 mm Hg ( 0 °C)
Flash Point: 500°C
Storage temp.: 2-8°C
Form: beads
Water Solubility: soluble
Sensitive: Hygroscopic
Sublimation: 500 ºC
Merck: 14,2437

  Cobaltous chloride (CAS NO.7646-79-9) is common used for the detection of moisture, for example in drying agents such as silica gel. When cobalt(II) chloride is added as an indicator, the drying agent is pink when exhausted,blue when still active, corresponding to anhydrous and hydrated CoCl₂, respectively. Similarly, "cobalt chloride paper",that is paper impregnated with cobalt chloride,is used to detect the presence of water. The rose hexahydrate of it is one of the most common cobalt compounds in the laboratory.

  Cobaltous chloride (CAS NO.7646-79-9) can be prepared in its anhydrous form from cobalt metal and chlorine gas:
 Co (s) + Cl₂ (g) → CoCl₂ (s)
The hydrated form of Cobalt(II) chloride (7646-79-9) can be prepared from cobalt(II) hydroxide or cobalt(II) carbonate and hydrochloric acid :
Co₂+ (aq) + 2Cl− (aq) → CoCl₂ (aq)

 Cobaltous chloride (CAS NO.7646-79-9) is reported in EPA TSCA Inventory. EPA Genetic Toxicology Program. Cobalt and its compounds are on the Community Right-To-Know List.

Hazard Codes of Cobaltous chloride (CAS NO.7646-79-9): T,N
Risk Statements: 49-42/43-52/53-50-22 
R49: May cause cancer by inhalation. 
R42/43: May cause sensitization by inhalation and skin contact. 
R52/53: Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 
R50: Very toxic to aquatic organisms. 
R22: Harmful if swallowed.
Safety Statements: 53-23-36/37-45-60-61-22 
S53: Avoid exposure - obtain special instructions before use. 
S23: Do not breathe vapour. 
S36/37: Wear suitable protective clothing and gloves. 
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S60: This material and its container must be disposed of as hazardous waste. 
S61: Avoid release to the environment. Refer to special instructions / safety data sheets. 
S22: Do not breathe dust.
RIDADR: UN 2923 8/PG 3
WGK Germany: 2
RTECS: GF9800000
F: 9-21
HazardClass: 8
PackingGroup: III
Poison experimentally by ingestion, skin contact, intraperitoneal, intravenous, and subcutaneous routes. Moderately toxic to humans by ingestion. Human systemic effects by ingestion: anorexia, goiter (increased thyroid size), and weight loss. Experimental teratogenic and reproductive effects.  When heated to decomposition it emits toxic fumes of Cl⁻.

The term " Cobaltous chloride " is used also to refer to the hexahydrate,CoCl₂ is blue, and CoCl₂·6H₂O is deep rose.CoCl₂·6H₂O is deliquescent and the anhydrous salt CoCl₂ is hygroscopic, readily converting to the hydrate.
The existence of Cobalt(III) chloride , CoCl₃, is disputed, although it is listed in some compendia.
Other informations about Cobaltous chloride (CAS NO.7646-79-9):
1.Fire Fighting Measures 
General Information: As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Substance is noncombustible. 
Extinguishing Media: Use extinguishing media most appropriate for the surrounding fire. Use water spray, dry chemical, carbon dioxide, or chemical foam. 
2.Handling and Storage:
Handling: Do not get on skin and clothing. Do not breathe dust, vapor, mist, or gas. Do not get in eyes, on skin, or on clothing. Use only in a chemical fume hood.
Storage: Store in a cool, dry place. Store in a tightly closed container.