Sodium azide (NaN3) is a chemical compound. It’s highly toxic and explosive. It’s used in airbags to rapidly generate nitrogen gas for inflation upon impact.
| IUPAC Name | Sodium Azide |
| Molecular Formula | NaN3 |
| CAS Number | 26628-22-8 |
| Synonyms | Azium, Hydrazoic Acid Sodium Salt, Sodium Trinitride |
| InChI | InChI=1S/3HNO.Na/c1-4-2;2-1-3;/h3*1H;/q;;;+1/p-1 |
Sodium Azide Properties
Sodium Azide Formula
The formula of sodium azide is NaN3. It consists of one sodium atom (Na) and three nitrogen atoms (N). The sodium atom is positively charged, while the nitrogen atoms are negatively charged. The formula represents the ratio of sodium to nitrogen atoms in the compound.
Sodium Azide Molar Mass
The molar mass of sodiumazide is calculated by adding up the atomic masses of its constituents. Sodium has a molar mass of 22.99 g/mol, and nitrogen has a molar mass of 14.01 g/mol. Since there are three nitrogen atoms in sodiumazide, we multiply the molar mass of nitrogen by three. Adding these values together gives a molar mass of approximately 65.01 g/mol for sodiumazide.
Sodium Azide Boiling Point
Sodiumazide has a high boiling point. When heated, it undergoes decomposition rather than boiling. At temperatures above 275 degrees Celsius (527 degrees Fahrenheit), it rapidly decomposes into sodium metal and nitrogen gas. Therefore, it does not have a well-defined boiling point.
Sodium Azide Melting Point
The melting point of sodiumazide is relatively low compared to its boiling point. It melts at around 275 degrees Celsius (527 degrees Fahrenheit). The compound changes from a solid to a liquid state at this temperature. However, it’s important to handle sodiumazide with caution due to its toxic and explosive nature.
Sodium Azide Density g/mL
The density of sodiumazide is commonly expressed in grams per milliliter (g/mL). The approximate density of solid sodiumazide is around 1.85 g/mL. However, it’s worth noting that the density may vary slightly depending on factors such as temperature and pressure.
Sodium Azide Molecular Weight
The molecular weight of sodiumazide is the sum of the atomic masses of its constituent elements. As mentioned earlier, sodiumazide consists of one sodium atom and three nitrogen atoms. By adding up the atomic masses of these elements, we obtain a molecular weight of approximately 65.01 grams per mole (g/mol).
Sodium Azide Structure
The structure of sodiumazide consists of alternating sodium cations (Na+) and azide anions (N3-). The sodium ion is surrounded by three nitrogen atoms, each of which shares one electron pair with the sodium atom. This arrangement creates a stable crystal lattice structure for sodiumazide.
Sodium Azide Solubility
Sodiumazide is moderately soluble in water. It dissolves in water to form a clear solution. The solubility of sodiumazide increases with higher temperatures. However, it is important to handle the solution with care due to the toxic and explosive nature of sodiumazide.
| Appearance | White solid |
| Specific Gravity | 1.85 g/mL |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 65.01 g/mol |
| Density | 1.85 g/mL |
| Melting Point | 275°C |
| Boiling Point | Decomposes |
| Flash Point | Not applicable |
| Water Solubility | Moderately soluble |
| Solubility | Soluble in polar solvents like ammonia |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| pKa | Not applicable |
| pH | Neutral |
Sodium Azide Safety and Hazards
Sodiumazide poses significant safety hazards and must be handled with utmost caution. It is highly toxic if ingested, inhaled, or absorbed through the skin. Exposure to sodiumazide can lead to severe health risks, including respiratory problems, dizziness, and even fatality. It is also a potential explosion hazard, especially when subjected to heat, shock, or contact with certain metals. When working with sodium azide, individuals must wear proper personal protective equipment, including gloves and safety glasses. It is crucial to store and handle this compound in well-ventilated areas, away from ignition sources and incompatible substances to minimize the risk of accidents and ensure workplace safety.
| Hazard Symbols | Toxic, Explosive |
| Safety Description | Handle with extreme caution. Toxic and explosive substance. |
| UN IDs | UN1687 (for sodiumazide, toxic solids, inorganic, n.o.s.) |
| HS Code | 28500090 |
| Hazard Class | 6.1 (Toxic substances) |
| Packing Group | II (Moderately dangerous substance) |
| Toxicity | Highly toxic |
Sodium Azide Synthesis Methods
There are a few common methods for synthesizing sodiumazide.
One method involves the reaction between sodium amide (NaNH2) and hydrazoic acid (HN3). In this method, dissolve sodium amide in liquid ammonia, and then add hydrazoic acid slowly. The reaction takes place, resulting in the formation of sodiumazide and ammonium chloride as a byproduct.
Another synthesis method involves the reaction between sodium nitrite (NaNO2) and sodiumazide (NaN3). In an aqueous solution, the reaction carefully controls the addition of sodium nitrite to a solution of sodiumazide, leading to the formation of sodiumazide and sodium nitrate.
To synthesize sodiumazide, one can react with sodium cyanide (NaCN) with nitrous oxide (N2O) at high temperatures. During this reaction, sodiumazide and sodium cyanate are formed as byproducts.
Always follow proper safety precautions to minimize risks associated with the synthesis process. This includes using personal protective equipment and adhering to handling protocols.
Sodium Azide Uses
Sodiumazide has several important uses across various industries. Here are some notable applications:
- Airbag inflation: Sodiumazide is a key component in automotive airbags. During a collision, a small amount of sodiumazide reacts rapidly to generate nitrogen gas, inflating the airbag and protecting passengers.
- Biochemical Research: Researchers use sodiumazide to inhibit enzymes, such as cytochrome oxidase, aiding the study of cellular processes and metabolic pathways.
- Preservation of Biological Samples: Sodiumazide preserves biological samples, such as antibodies, by preventing bacterial growth and maintaining their stability.
- Explosive Initiation: Sodiumazide serves as a primary explosive in certain pyrotechnic devices, detonators, and initiators for explosives due to its explosive nature.
- Chemical Synthesis: Sodiumazide acts as a precursor in various chemical reactions, enabling the synthesis of organic compounds, pharmaceuticals, and dyes.
- Corrosion Prevention: Industries use sodiumazide as a corrosion inhibitor to protect metal surfaces from degradation caused by oxidation or exposure to corrosive agents.
- Mining Industry: Sodiumazide assists in the separation of valuable minerals from unwanted substances in mining operations as a depressant in mineral flotation processes.
- Polymer Industry: Sodiumazide acts as a blowing agent in the production of polyurethane foams, facilitating the formation of gas bubbles that give the foam its desired structure.
- Analytical Chemistry: Sodiumazide serves as a reagent for various chemical analyses, including spectrophotometry, gas chromatography, and mass spectrometry.
- Veterinary Medicine: Veterinarians utilize sodiumazide as a euthanasia agent for animals in some cases within veterinary practice.
These applications highlight the diverse utility of sodiumazide, but it is crucial to handle this compound with care and adhere to safety protocols due to its toxic and explosive nature.
Questions
Q: How to test sodium azide?
A: Sodiumazide can be tested using appropriate analytical techniques such as spectroscopy, chromatography, or chemical reactivity tests.
Q: Is sodium azide still used in airbags?
A: Yes, sodiumazide is still used in airbags as a propellant for rapid inflation upon impact.
Q: How many grams of sodium azide are required to produce 30.5 g of nitrogen?
A: Approximately 34 grams of sodiumazide are required to produce 30.5 grams of nitrogen gas.
Q: Where to buy sodium azide?
A: Sodiumazide can be purchased from chemical suppliers, laboratory suppliers, or online chemical marketplaces.
Q: How to make 0.01% sodium azide solution in PBS?
A: To make a 0.01% sodiumazide solution in PBS, dissolve 0.01 grams of sodiumazide in 100 mL of PBS (Phosphate Buffered Saline) solution.
Q: What is the role of sodium azide in experiments?
A: Sodiumazide is commonly used as an inhibitor or preservative in experiments to inhibit enzyme activity or prevent bacterial growth.
Q: How to purge sodium azide from a sample?
A: Sodiumazide can be purged from a sample by thorough washing or rinsing with appropriate solvents or by subjecting it to high-temperature decomposition.
Q: How does sodium azide affect the ETC?
A: Sodiumazide inhibits the Electron Transport Chain (ETC) in mitochondria by blocking the cytochrome oxidase enzyme, interrupting the flow of electrons and ATP production.
Q: How many grams of Sodium are formed when 93 grams of Sodium Azide is allowed to react?
A: 35.9 grams of Sodium are formed when 93 grams of sodiumazide is allowed to react.
Q: Is explosive decomposition of sodium azide a physical change in airbag inflation?
A: No, the explosive decomposition of sodiumazide to inflate an automobile airbag is a chemical change.
Q: How to prepare sodium azide?
A: Sodiumazide is typically prepared through chemical synthesis methods involving reactions between suitable precursors, such as sodium amide and hydrazoic acid.
Q: How much sodium azide is toxic?
A: Sodiumazide is highly toxic, and even small amounts, such as a few grams, can pose significant health risks if ingested, inhaled, or absorbed through the skin.
Q: What is sodium azide used for?
A: Sodiumazide is used in various applications, including airbag inflation, biochemical research, chemical synthesis, and as a preservative or inhibitor in biological samples.
Q: Does sodium azide react with acids?
A: Yes, sodiumazide can react with acids, such as hydrochloric acid (HCl), forming toxic gases like hydrogen azide (HN3). Proper precautions should be taken when handling sodiumazide and acids.