Sodium nitrite (NaNO2) is a chemical compound commonly used as a food preservative to prevent bacterial growth and enhance color and flavor in cured meats like bacon and hot dogs.
| IUPAC Name | Sodium nitrite |
| Molecular Formula | NaNO2 |
| CAS Number | 7632-00-0 |
| Synonyms | Nitrous acid, sodium salt; E250; Natriumnitrit; Nitrite de sodium; Nitrito sodico; UN 1500 |
| InChI | InChI=1S/NO2.Na/c2-1-3;/q-1;+1 |
Sodium Nitrite Properties
Sodium Nitrite Formula
The chemical formula for sodium nitrite is NaNO2. This indicates that one mole of sodium nitrite contains one sodium cation, one nitrogen atom, and two oxygen atoms. The formula is used to represent the composition of a substance and can be used to predict the reactions that a substance may undergo.
Sodium Nitrite Molar Mass
NaNo2 has a molar mass of 69.0 g/mol. This is the mass of one mole of NaNo2, which is the amount of substance that contains 6.02 x 10^23 individual molecules of the compound. Molar mass is an important physical property used to calculate various chemical and physical properties of a substance.
Sodium Nitrite Boiling Point
The boiling point of NaNo2 is 320°C (608°F). This is the temperature at which NaNo2 will change from a liquid to a gas. The boiling point is an important property because it can affect how a substance is used in various industrial applications, such as in the production of dyes, pigments, and pharmaceuticals.
Sodium Nitrite Melting Point
The melting point of NaNo2 is 271°C (520°F). This is the temperature at which NaNo2 will change from a solid to a liquid. The melting point is an important property because it can affect the stability and reactivity of a substance at different temperatures.
Sodium Nitrite Density g/mL
The density of NaNo2 is 2.168 g/mL. Density is the mass per unit volume of a substance, and it can be used to determine the concentration of a solution. The density of NaNo2 can also be used to determine the purity of a sample.
Sodium Nitrite Molecular Weight
The molecular weight of NaNo2 is 69.0 g/mol. This is the sum of the atomic weights of all the atoms in one molecule of the compound. Molecular weight is an important property used to calculate various chemical and physical properties of a substance.
Sodium Nitrite Structure
The structure of NaNo2 is composed of one sodium cation (Na+) and one nitrite anion (NO2-). The nitrite anion has a trigonal planar geometry with one nitrogen atom and two oxygen atoms. The sodium cation is located in the center of the nitrite anion.
Sodium Nitrite Solubility
NaNo2 is soluble in water, with a solubility of 820 g/L at 20°C. Solubility is the maximum amount of a substance that can be dissolved in a given amount of solvent at a given temperature. The solubility of NaNo2 can be affected by factors such as temperature and the presence of other solutes.
| Appearance | White to slightly yellowish crystalline powder |
| Specific Gravity | 2.168 g/mL |
| Color | White to slightly yellowish |
| Odor | Odorless |
| Molar Mass | 69.0 g/mol |
| Density | 2.168 g/mL |
| Melting Point | 271°C (520°F) |
| Boiling Point | 320°C (608°F) |
| Flash Point | Not applicable |
| Water Solubility | 820 g/L at 20°C |
| Solubility | Soluble in ethanol and glycerol |
| Vapour Pressure | 1.33 kPa at 20°C |
| Vapour Density | 2.3 (air = 1) |
| pKa | 3.34 |
| pH | 7-8 (10% solution) |
Sodium Nitrite Safety and Hazards
NaNo2 can pose a number of hazards to human health and the environment. It is considered to be toxic if ingested, inhaled, or absorbed through the skin, and can cause methemoglobinemia, a condition where the blood is unable to carry oxygen to the body’s tissues. NaNo2 can also be an irritant to the eyes, skin, and respiratory system. It is important to handle NaNo2 with caution, using appropriate personal protective equipment and following proper handling and disposal procedures. Additionally, NaNo2 can pose a risk to the environment if not properly contained and disposed of.
| Hazard Symbols | T+, C |
| Safety Description | Keep away from combustible materials. Do not breathe dust/fume/gas/mist/vapours/spray. Wear protective gloves/clothing and eye/face protection. In case of fire: Use CO2, dry chemical, or foam for extinction. Dispose of contents/container in accordance with local/regional/national/international regulations. |
| UN IDs | UN1500 |
| HS Code | 283410 |
| Hazard Class | 5.1 |
| Packing Group | II |
| Toxicity | Highly toxic by ingestion, inhalation, and skin absorption. May cause methemoglobinemia. Irritating to eyes, skin, and respiratory system. |
Sodium Nitrite Synthesis Methods
There are several methods to synthesize NaNo2.
One common method is through the reaction of nitric acid and sodium hydroxide, which produces sodium nitrate. A reducing agent such as iron or zinc reduces sodium nitrate, thereby forming NaNo2.
Another method involves the reaction of sodium nitrate with hydrochloric acid, producing a mixture of nitric acid and sodium chloride. Sodium hydroxide reacts with nitric acid to produce NaNo2.
The synthesis of NaNo2 can occur through the reaction between ammonia and sodium nitrate, which produces NaNo2 and water as products.
The manufacturing process of nitric acid produces NaNo2 as a byproduct while oxidizing ammonia during the process.
Sodium Nitrite Uses
NaNo2 has a variety of uses across various industries, some of which include:
- Food preservation: Commonly used as a food preservative, particularly in cured meats like bacon and hot dogs. It helps prevent the growth of harmful bacteria and preserves the meat’s color and flavor.
- Industrial applications: Used in various industrial applications, such as metal treatment and as a corrosion inhibitor. Also used in the production of dyes and other chemicals.
- Medical applications: Used in medicine to treat cyanide poisoning, as it converts hemoglobin to methemoglobin, which can bind to cyanide ions and prevent them from binding to hemoglobin.
- Water treatment: Used in water treatment to control the growth of harmful bacteria and algae in water systems.
- Agriculture: Used in agriculture as a fertilizer, helping to improve crop yields and quality.
- Photography: Used in photography as a developing agent.
Questions:
Q: What is sodium nitrite?
A: NaNo2 is a chemical compound with the formula NaNO2. It is a white or slightly yellowish crystalline powder that is commonly used as a food preservative and in various industrial applications.
Q: Who discovered sodium nitrite?
A: NaNO2 was first discovered in 1805 by the French chemist Louis Nicolas Vauquelin.
Q: Is sodium nitrite bad for you?
A: Excessive consumption of NaNo2 can be harmful to human health. It has been linked to health concerns such as cancer and methemoglobinemia, a condition in which the blood is unable to carry oxygen effectively. However, when used in regulated and limited amounts, NaNo2 is considered safe for consumption.
Q: What is the formula for sodium nitrite?
A: The formula for sodium nitrite is NaNO2.
Q: Is sodium nitrite safe?
A: NaNo2 is generally considered safe for consumption when used in regulated and limited amounts. However, excessive consumption can be harmful to human health.
Q: How to make sodium nitrite?
A: NaNo2 can be synthesized through various methods, such as the reaction of nitric acid and sodium hydroxide, the reaction of sodium nitrate with hydrochloric acid, and the reaction of ammonia with sodium nitrate. However, the synthesis of NaNo2 should be carried out with caution, as it involves the use of hazardous chemicals and requires appropriate safety measures to be taken.
Q: Is sodium nitrite an oxidizer?
A: Yes, NaNo2 is an oxidizer. It is commonly used in pyrotechnics as an oxidizing agent.
Q: How does sodium nitrite affect meat color?
A: NaNO2 is commonly used as a food preservative in cured meats like bacon and hot dogs. It helps preserve the meat’s color by inhibiting the growth of harmful bacteria that can cause discoloration.
Q: How are NaNO2 and NaNO3 commercially produced?
A: NaNO3 and NaNO2 are commercially produced through various methods, such as the oxidation of ammonia and the reaction of sodium hydroxide with nitric acid. They are used in a variety of industrial, medical, and agricultural applications, as well as in food preservation.