Calcium chloride (CaCl2) is a white, crystalline, soluble salt that can form several hydrates:
Calcium chloride monohydrate CaCl2•H2O
Calcium chloride dihydrate CaCl2•2H2O
Calcium chloride tetra hydrate CaCl2•4H2O
Calcium chloride hexahydrate CaCl2•6H2O
The physical properties of the anhydrous salt and hydrates are given below
| |
CaCl2
|
CaCl2∙H20 |
CaCl2∙2H20 |
CaCl2∙4H20 |
CaCl2∙6H20 |
|
CAS#
|
10043-52-4
|
22691-02-07
|
10035-04-8 |
25094-02-4 |
7774-34-7 |
| Molecular Wt. |
111
|
129
|
147
|
183
|
219
|
| % CaCl2 |
100
|
86.03
|
75.49
|
60.63
|
50.66
|
| % Water |
0
|
13.97
|
24.51
|
39.37
|
49.34
|
Melting Point,
°C |
772
|
260
|
176
|
45
|
30
|
| Density1, g/cm3 |
2.22
|
2.24
|
1.85
|
1.83
|
1.72
|
| Heat of hydration, kJ/kg |
-
|
-240
|
-295
|
-600
|
-840
|
| Heat of solution, kJ/kg |
-680
|
-380
|
-290
|
-50
|
80
|
Specific heat,
J/(K•kg) |
670
|
840
|
1170
|
1340
|
1420
|
| Vapor pressure in mbar @ 25°C |
-
|
undetectable
|
1
|
4
|
7
|
1Indicates the density of the crystal, not the bulk density
Solubility for anhydrous calcium chloride in a few organic solvents is given below.
Methanol
At temperatures below 55°C CaCl2, forms CaCl2·4CH3OH with methanol and below 55°C CaCl2·3CH3OH is formed.
|
Temperature, °C
|
% CaCl2
|
| 0 |
15.5
|
| 10 |
17.5
|
| 20 |
19.6
|
| 30 |
21.9
|
| 40 |
24.2
|
| 50 |
26.7
|
| 55 |
27.9
|
| 75 |
33.9
|
Ethanol
CaCl2 forms CaCl2·3C2H5OH with ethanol.
|
Temperature, °C
|
% CaCl2
|
| 0 |
15.5
|
| 10 |
17.9
|
| 20 |
20.5
|
| 30 |
23.2
|
| 50 |
29.2
|
Acetone
0.08 g/L at 20°C
Glycerine
Readily soluble. At high concentrations a “glass” is formed.
Diethyl ether
Sparingly soluble | 
