Sodium formate

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Sodium formate
Names
IUPAC name
Sodium formate
Other names
Formic acid, sodium salt
Properties
HCOONa
Molar mass 68.007 g/mol
Appearance White hygroscopic solid
Odor Odorless
Density 1.92 g/cm3 (20 °C)
Melting point 253 °C (487 °F; 526 K)
Boiling point Decomposes
43.82 g/100 mL (0 °C)
97.2 g/100 mL (20 °C)
160 g/100 mL (100 °C)
Solubility Soluble in ethanol, formic acid, methanol
Slightly soluble in glycerol
Insoluble in diethyl ether, toluene
Vapor pressure ~0 mmHg
Acidity (pKa) 7.0-8.5 (0.1 M)
Thermochemistry
103.8 J·mol−1·K−1
-666.5 kJ/mol
Hazards
Safety data sheet FischerScintific
Flash point Non-flammable
Related compounds
Related compounds
Calcium formate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium formate is the sodium salt of formic acid, with the chemical formula HCOONa or HCO2Na.

Properties

Chemical

Adding a strong acid, like sulfuric acid will give sodium sulfate and formic acid.

2 HCOONa + H2SO4 → 2 HCOOH + Na2SO4

If the acid is too concentrated, carbon monoxide will evolve.

2 HCOONa + H2SO4 → Na2SO4 + 2 H2O + CO + CO2

Physical

Sodium formate is a hygroscopic colorless salt, soluble in water and formic acid. It decomposes when heated above 253°C.

Availability

Some commercial deicers are ~90% sodium formate.

Lastly it can be purchased from chemical suppliers.

Preparation

There are several routes to formic acid.

The simplest way is to slowly add sodium bicarbonate to a concentrated solution of formic acid.

NaHCO3 + HCOOH → HCOONa + H2O + CO2

The solution is then cooled to precipitate the sodium formate which is filtered and dried.

The haloform reaction of ethanol/acetaldehyde and sodium hypochlorite will yield chloroform and sodium formate.

Projects

Handling

Safety

Sodium formate is irritant and should be handled with proper protection. Contact with strong acids should be avoided as it will generate formic acid and carbon monoxide.

Storage

Sodium formate should be stored in closed bottles, away from acids.

Disposal

Heating it in a kiln will cause it to break down into sodium carbonate, carbon monoxide and water vapor.

References

Relevant Sciencemadness threads