Sodium hydride
Sodium hydride is the chemical compound with the empirical formula NaH. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na+ and H− ions, in contrast to molecular hydrides such as borane, methane, ammonia, water, and hydrogen fluoride. It is an ionic material that is insoluble in all solvents (other than molten Na), consistent with the fact that H− ions do not exist in solution.
Sodium cation, Na+ Hydrogen anion, H− | |
Names | |
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IUPAC name
Sodium hydride | |
Identifiers | |
3D model (JSmol) |
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ChemSpider | |
ECHA InfoCard | 100.028.716 |
EC Number |
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PubChem CID |
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UNII | |
CompTox Dashboard (EPA) |
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Properties | |
NaH | |
Molar mass | 23.998 g/mol |
Appearance | white or grey solid |
Density | 1.39 g/cm3 |
Melting point | 638 °C (1,180 °F; 911 K)(decomposes) |
Reacts with water | |
Solubility | insoluble in all solvents |
Band gap | 3.51 eV (predicted) |
Refractive index (nD) |
1.470 |
Structure | |
fcc (NaCl), cF8 | |
Fm3m, No. 225 | |
a = 498 pm | |
Formula units (Z) |
4 |
Octahedral (Na+) Octahedral (H−) | |
Thermochemistry | |
Heat capacity (C) |
36.4 J/mol K |
Std molar entropy (S⦵298) |
40.0 J·mol−1·K−1 |
Std enthalpy of formation (ΔfH⦵298) |
−56.3 kJ·mol−1 |
Gibbs free energy (ΔfG⦵) |
-33.5 kJ/mol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards |
highly corrosive, pyrophoric in air, reacts violently with water. |
GHS labelling: | |
Danger | |
H260 | |
NFPA 704 (fire diamond) | |
Flash point | combustible |
Safety data sheet (SDS) | External MSDS |
Related compounds | |
Other anions |
Sodium borohydride Sodium hydroxide |
Other cations |
Lithium hydride Potassium hydride Rubidium hydride Caesium hydride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
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