Sodium hydride (NaH) is a chemical compound. It consists of sodium and hydrogen atoms. NaH reacts vigorously with water, releasing hydrogen gas and forming sodium hydroxide.
| IUPAC Name | Sodium Hydride |
| Molecular Formula | NaH |
| CAS Number | 7646-69-7 |
| Synonyms | Sodium Hydride, Sodium Monohydride, Hydridosodium |
| InChI | InChI=1S/Na.H |
Sodium Hydride Properties
Sodium Hydride Formula
The formula of sodium monohydride is NaH. It represents the chemical composition of the compound, consisting of one sodium atom (Na) and one hydrogen atom (H). Sodium monohydride is an ionic compound formed by the transfer of an electron from sodium to hydrogen.
Sodium Hydride Molar Mass
The molar mass of sodium monohydride is calculated by adding the atomic masses of sodium and hydrogen. Sodium has an atomic mass of 22.99 grams per mole (g/mol), while hydrogen has an atomic mass of 1.01 g/mol. Thus, the molar mass of sodium monohydride is approximately 23.99 g/mol.
Sodium Hydride Boiling Point
Sodium monohydride does not have a distinct boiling point. It undergoes decomposition when exposed to high temperatures, liberating hydrogen gas and forming sodium metal. Therefore, it is not commonly used as a boiling point reference substance.
Sodium Hydride Melting Point
The melting point of sodium monohydride is relatively high. It typically melts at around 800 degrees Celsius (1472 degrees Fahrenheit). At this temperature, the ionic lattice structure of NaH breaks down, allowing the compound to transition from a solid to a liquid state.
Sodium Hydride Density g/mL
The density of sodium monohydride can vary depending on its crystalline form and purity. On average, sodium monohydride has a density of about 1.39 grams per milliliter (g/mL). This density value indicates that sodium monohydride is denser than water, as water has a density of 1 g/mL.
Sodium Hydride Molecular Weight
The molecular weight of sodium monohydride is calculated by summing the atomic weights of its constituent atoms. With sodium having an atomic weight of 22.99 grams per mole (g/mol) and hydrogen having an atomic weight of 1.01 g/mol, the molecular weight of sodium monohydride is approximately 23.99 g/mol.
Sodium Hydride Structure
Sodium monohydride adopts a crystal lattice structure. Each sodium ion (Na+) is surrounded by six hydrogen ions (H-) in a close-packed arrangement. The sodium cations and hydride anions are held together by strong ionic bonds, creating a solid, crystalline structure.
Sodium Hydride Solubility
Sodium monohydride is sparingly soluble in most solvents. It reacts violently with water, releasing hydrogen gas and forming sodium hydroxide. However, it can dissolve in certain polar solvents such as liquid ammonia (NH3), forming a solution of sodium amide (NaNH2). This solubility behavior is due to the strong ionic nature of sodium monohydride.
| Appearance | White to gray solid |
| Specific Gravity | 0.92 |
| Color | White to gray |
| Odor | Odorless |
| Molar Mass | 23.99 g/mol |
| Density | 1.39 g/mL |
| Melting Point | 800°C (1472°F) |
| Boiling Point | Decomposes |
| Flash Point | Not applicable |
| Water Solubility | Reacts vigorously |
| Solubility | Sparingly soluble in some solvents, dissolves in ammonia |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| pKa | Not applicable |
| pH | Not applicable |
Sodium Hydride Safety and Hazards
Sodium monohydride poses certain safety hazards that should be taken into consideration. It reacts violently with water, producing highly flammable hydrogen gas, which can lead to fire or explosions. Thus, it is crucial to handle sodium monohydride with extreme caution, ensuring proper storage and protection from moisture. The compound can cause severe burns when in contact with skin or eyes, so protective gloves and goggles are essential when working with it. In addition, sodium monohydride should be kept away from oxidizing agents, as it can react vigorously with them. Proper ventilation and adherence to safety protocols are necessary to minimize the risks associated with sodium monohydride.
| Hazard Symbols | Danger |
| Safety Description | Highly flammable and reactive. Handle with extreme caution. |
| UN IDs | UN 1427 |
| HS Code | 28500010 |
| Hazard Class | 4.3 |
| Packing Group | II |
| Toxicity | Highly toxic upon ingestion or inhalation. |
Sodium Hydride Synthesis Methods
There are a few common methods for synthesizing sodium monohydride.
One method involves the reaction between sodium metal (Na) and hydrogen gas (H2). The reaction takes place at elevated temperatures and requires a controlled environment to prevent unwanted side reactions. Sodium metal reacts with hydrogen gas under the influence of heat, producing sodium monohydride (NaH).
Another synthesis method involves the reaction between sodium hydroxide (NaOH) and a hydride source, such as lithium aluminum hydride (LiAlH4) or lithium hydride (LiH). The reaction mixture combines sodium hydroxide with the hydride source while employing a suitable solvent such as diethyl ether or tetrahydrofuran to assist the reaction. This reaction leads to the formation of sodium monohydride and the corresponding salt of the hydride source.
To prepare sodium monohydride, one can react with sodium borohydride (NaBH4) with a strong base, such as sodium monohydride or sodium amide (NaNH2). In this process, we use a strong base to treat sodium borohydride, which produces sodium monohydride and the corresponding borate salt.
It is worth noting that the synthesis of sodium monohydride requires careful handling due to its reactivity with air and moisture. To prevent undesired reactions, individuals commonly perform the procedure with sodium monohydride under inert atmospheres, such as nitrogen or argon. When working with sodium monohydride, it is essential to follow safety precautions, use protective equipment, and adhere to proper handling procedures.
Sodium Hydride Uses
Sodium monohydride (NaH) finds applications in various fields due to its unique properties. Here are some common uses of sodium monohydride:
- Desiccant: Sodium monohydride actively removes traces of moisture from solvents and gases, serving as an efficient desiccant. Its reactivity with water allows it to absorb and neutralize water molecules.
- Hydrogen source: Sodium monohydride serves as a source of hydrogen gas in various chemical reactions. It readily releases hydrogen when exposed to moisture or acids, making it useful in hydrogenation processes and as a reducing agent.
- Deprotonation agent: Organic synthesis utilizes sodium monohydride as a deprotonating agent because of its potent basic nature. It can remove acidic protons from various compounds, facilitating reactions such as the deprotonation of amines or carboxylic acids.
- Catalyst precursor: Sodium monohydride serves as a precursor for preparing catalysts by reacting with specific transition metal compounds, thereby forming catalysts utilized in organic reactions.
- Polymerization initiator: In polymer chemistry, sodium monohydride can function as an initiator for the polymerization of certain monomers. Its reactivity aids in the initiation of polymerization reactions, leading to the formation of polymers with desired properties.
- Synthetic reagent: Sodium monohydride acts as a versatile reagent in organic synthesis, participating in various reactions such as alkylation, condensation, and dehalogenation. Its strong basicity and ability to generate reactive intermediates make it useful in complex organic transformations.
- Pharmaceutical synthesis: Sodium monohydride finds application in the synthesis of pharmaceutical compounds. It can play a role in several steps, including unmasking functional groups, performing reduction reactions, or participating as a reactant in particular drug synthesis pathways.
Questions:
Q: What is sodium hydride?
A: Sodium monohydride is a chemical compound consisting of sodium (Na) and hydrogen (H) atoms.
Q: What is the formula for sodium hydride?
A: The formula for sodium monohydride is NaH.
Q: How many molar equivalents of hydride does sodium borohydride contain?
A: Sodium borohydride (NaBH4) contains four molar equivalents of hydride (H^-) ions.
Q: Does sodium hydride react with acetonitrile?
A: Yes, sodium monohydride can react with acetonitrile (CH3CN) to form various products, depending on the reaction conditions.
Q: How to quench sodium hydride?
A: Sodium monohydride can be quenched by adding a suitable quenching agent such as water, alcohols, or weak acids, to neutralize the reactivity of the hydride ions.
Q: Is NaH a strong base?
A: Yes, NaH is considered a strong base due to its ability to readily accept protons (H+) in reactions.
Q: Is NaH an acid or base?
A: NaH is a base, as it can donate electrons or accept protons to form a negatively charged monohydride ion (H^-).
Q: What is NaH?
A: NaH is the chemical symbol for sodium monohydride, an ionic compound commonly used in various chemical reactions.
Q: Show me the formula for sodium hydride.
A: The formula for sodium monohydride is NaH.
Q: Sodium monohydride pKa?
A: Sodium monohydride does not have a pKa value as it is not an acid or a compound that donates protons.
Q: Nah sodium hydride?
A: “Nah” is a casual slang term and not related to sodium monohydride.