Sodium aluminium hydride

Sodium aluminium hydride

Names
IUPAC name Sodium aluminium hydride
Other names Aluminum sodium hydride Sodium alanate Sodium tetrahydroaluminate
Properties
Chemical formula	NaAlH4
Molar mass	54.003 g/mol
Appearance	White crystalline solid
Odor	Odorless
Density	1.24 g/cm3
Melting point	183 °C (361 °F; 456 K) (decomposes)
Boiling point	Decomposes
Solubility in water	Reacts
Solubility	Reacts with alcohols, carboxylic acids, halocarbons Soluble in diglyme Insoluble in diethyl ether, hydrocarbons
Solubility in tetrahydrofuran	16 g/100 ml
Vapor pressure	~0 mmHg
Thermochemistry
Std molar entropy (So298)	89.12 J·mol-1·K-1
Std enthalpy of formation (ΔfHo298)	-117.04 kJ/mol
Hazards
Safety data sheet	Sigma-Aldrich
Related compounds
Related compounds	Lithium aluminium hydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium aluminium hydride, also known as sodium alanate is an white pyrophoric solid, with the chemical formula NaAlH₄, used as a reducing agent in place of the more expensive lithium aluminium hydride, even though it's reducing potential is weaker.

Properties

Chemical

Sodium aluminium hydride reacts with water, releasing hydrogen gas.

NaAlH₄ + 4 H₂O → NaAl(OH)₄ + 4 H₂

It is a powerful reducing agent, though lithium aluminium hydride is stronger.

Physical

Sodium aluminium hydride is an odorless white solid, which reacts with water, but is soluble in THF.

Availability

Sodium aluminium hydride is sold by chemical suppliers, though it's not easy to get hold of.

Preparation

Sodium aluminium hydride can be synthesized by reacting powdered sodium hydride and aluminium with hydrogen at 200 °C under high pressure (<100 atm). A catalyst, like triethylaluminium is used.

Projects

• Reduce organic compounds
• Make lithium aluminium hydride

Handling

Safety

Sodium aluminium hydride is corrosive, caustic and pyrophoric.

Storage

Sodium aluminium hydride is best in air tight containers. Keep it away from moisture and acidic vapors.

Disposal

Can be safely neutralized by slowly and carefully adding it in large amounts of water or an alcohol. Neutralization should be done outside.

References

Relevant Sciencemadness threads

• Preparation of Sodium Aluminum Hydride and Lithium Aluminum Hydride