Sodium formate
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| Names | |
|---|---|
| Other names
formic acid, sodium salt
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| Identifiers | |
| ECHA InfoCard | 100.004.990 |
| EC Number |
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| E number | E237 (preservatives) |
CompTox Dashboard (EPA)
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| Properties | |
| HCOONa | |
| Molar mass | 68.01 g/mol |
| Appearance | white granules deliquescent |
| Density | 1.92 g/cm3 (20°C) |
| Melting point | 253 °C |
| Boiling point | decomposes |
| 97 g/100 mL (20°C) | |
| Solubility | insoluble in ether soluble in glycerol, alcohol |
| Acidity (pKa) | 7.0-8.5 (0.1M) |
| Hazards | |
| NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder.
Uses
Sodium formate is used in several fabric dyeing and printing processes. It is also used as a buffering agent for strong mineral acids to increase their pH.
Preparation
Sodium formate can be prepared in the laboratory by neutralizing formic acid with sodium carbonate. It can also be obtained by reacting chloroform with an alcoholic solution of sodium hydroxide.
or by reacting sodium hydroxide with chloral hydrate.
- C2HCl3(OH)2 + NaOH → CHCl3 + HCOONa + H2O
The latter method is generally preferred to the former because the low aqueous solubility of CHCl3 makes it easier to separate out from the sodium formate solution, by fractional crystallization, than the soluble NaCl would be.
Commercially sodium formate is produced by absorbing carbon monoxide under pressure in solid sodium hydroxide at 160 °C
Sodium formate may also be created via the haloform reaction between ethanol and sodium hypochlorite in the presence of a base. This procedure is well-documented for the preparation of chloroform.
See also
References
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