Sodium acetate (C2H3NaO2) is a compound made of Na+ and C2H3O2- ions. It is commonly used as a food additive and in medical applications, such as in dialysis solutions, and as a source of carbon for certain bacteria.
| IUPAC Name | Sodium acetate |
| Molecular Formula | C2H3NaO2 |
| CAS Number | 127-09-3 |
| Synonyms | Acetic acid sodium salt, Sodium ethanoate, Natriumacetat |
| InChI | InChI=1S/C2H4O2.Na/c1-2(3)4;/h1H3,(H,3,4);/q;+1/p-1 |
Sodium Acetate Properties
Sodium Acetate Formula
The chemical formula of sodium acetate is NaC2H3O2. This indicates that the compound is made up of one Na+ ion and one C2H3O2- ion. The C2H3O2- ion is composed of a carbon atom, two oxygen atoms, and three hydrogen atoms. The formula is useful in determining the stoichiometry of chemical reactions and in predicting the behavior of the compound under different conditions.
Sodium Acetate Molar Mass
NaC2H3O2 has a molar mass of 82.03 g/mol. This means that one mole of NaC2H3O2 weighs 82.03 grams. The molar mass is calculated by adding up the atomic masses of each element in the compound. Sodium has a mass of 22.99 g/mol, carbon has a mass of 12.01 g/mol, hydrogen has a mass of 1.01 g/mol, and oxygen has a mass of 16.00 g/mol. The molar mass of NaC2H3O2 is useful in determining the amount of the compound present in a given sample.
Sodium Acetate Boiling Point
NaC2H3O2 has a boiling point of 881 °C (1,618 °F). The boiling point is the temperature at which a substance changes from a liquid to a gas. The high boiling point of NaC2H3O2 is due to the strong ionic bonds between the sodium and acetate ions. At high temperatures, these bonds are broken, and the compound vaporizes.
Sodium Acetate Melting Point
NaC2H3O2 has a melting point of 324 °C (615 °F). The melting point is the temperature at which a substance changes from a solid to a liquid. The high melting point of NaC2H3O2 is also due to the strong ionic bonds between the sodium and acetate ions. At high temperatures, these bonds are weakened, and the compound melts.
Sodium Acetate Density g/mL
NaC2H3O2 has a density of 1.45 g/mL. Density is the amount of mass per unit volume of a substance. The high density of NaC2H3O2 is due to the compact arrangement of its molecules. The density of NaC2H3O2 can vary depending on its concentration in a solution.
Sodium Acetate Molecular Weight
The molecular weight of NaC2H3O2 is 82.03 g/mol. This is the mass of one mole of the compound. The molecular weight is useful in determining the amount of a compound in a given sample, as well as in calculating the stoichiometry of chemical reactions.
Sodium Acetate Structure
NaC2H3O2 has a crystalline structure with a repeating unit of Na(CH3COO). This means that each unit cell of the crystal contains one sodium ion and one acetate ion. The Na+ ion is surrounded by six oxygen atoms, while the C2H3O2- ion is composed of a carbon atom, two oxygen atoms, and three hydrogen atoms. The strong ionic bonds between the ions give the crystal its stability and high melting and boiling points.
| Appearance | White crystalline solid |
| Specific Gravity | 1.45 at 20°C |
| Color | Colorless or white |
| Odor | Odorless |
| Molar Mass | 82.03 g/mol |
| Density | 1.45 g/cm³ at 20°C |
| Melting Point | 324°C (615°F) |
| Boiling Point | 881°C (1618°F) |
| Flash Point | Not applicable |
| Water Solubility | 820 g/L (20°C) |
| Solubility | Soluble in water, ethanol, acetone |
| Vapour Pressure | 1 mm Hg at 239.2 °C |
| Vapour Density | Not applicable |
| pKa | 4.76 (at 25°C) |
| pH | 7 (1% solution) |
Sodium Acetate Safety and Hazards
NaC2H3O2 is generally considered safe to handle and use when proper precautions are taken. However, it may cause skin and eye irritation, and ingestion or inhalation of large amounts may lead to gastrointestinal irritation, respiratory problems, and central nervous system depression. NaC2H3O2 can also react with strong oxidizing agents, acids, and alkalis, generating heat and hazardous gases. It is important to wear appropriate personal protective equipment when handling NaC2H3O2, including gloves and eye protection. NaC2H3O2 should be stored in a cool, dry, well-ventilated area, away from incompatible substances. In case of accidental exposure or ingestion, seek medical attention immediately.
| Hazard Symbols | None |
| Safety Description | Avoid contact with skin and eyes. Do not ingest or inhale. Use in well-ventilated areas. |
| UN IDs | Not regulated |
| HS Code | 2915.21.00 |
| Hazard Class | Not classified |
| Packing Group | Not applicable |
| Toxicity | Low toxicity |
Sodium Acetate Synthesis Methods
There are several methods for synthesizing NaC2H3O2, but the most common one involves the neutralization reaction of acetic acid and sodium hydroxide. The reaction equation is as follows:
CH3COOH + NaOH → CH3COONa + H2O
To carry out the reaction, a solution of acetic acid is first prepared by dissolving glacial acetic acid in water. While stirring, add sodium hydroxide slowly to the acetic acid solution until the pH of the solution reaches around 7.
At this point, the solution will contain NaC2H3O2 and water. To obtain solid NaC2H3O2, one can evaporate the solution using gentle heat until it dries out. Alternatively, one can let the solution cool to room temperature, and the NaC2H3O2 crystals will precipitate out on their own.
Another method for synthesizing NaC2H3O2 is through the reaction between acetic anhydride and sodium carbonate. The reaction equation is as follows:
2 (CH3CO)2O + Na2CO3 → 2 CH3COONa + CO2 + CO + H2O
This reaction produces NaC2H3O2, carbon dioxide, carbon monoxide, and water.
Evaporating the reaction mixture to dryness and then crystallizing it from water can yield NaC2H3O2 as a solid. The high cost of acetic anhydride makes this method uncommonly used.
Sodium Acetate Uses
NaC2H3O2 is a versatile chemical with many industrial and scientific applications. Here are some of its common uses:
- Buffering agent: Commonly used as a buffering agent in chemical and biological applications. It helps to maintain a stable pH and prevent fluctuations in acidity.
- Heat packs: Used in the production of heat packs or heat pads. These bags are small and can heat up to provide warmth to a specific area of the body.
- Food additive: Used as a food additive, mainly as a flavor enhancer, pH regulator, and preservative. Processed food manufacturers commonly include it in snacks, sauces, and meat products.
- Textile industry: Used in the textile industry as a dyeing and printing auxiliary. It helps to improve the dye uptake and color fastness of fabrics.
- Chemical synthesis: Used as a reagent in various chemical reactions. It converts alcohols to their corresponding alkyl halides and produces acetic anhydride from acetic acid.
- Medical applications: Used in medical applications such as hemodialysis and as a component of electrolyte solutions.
- Photography: Used in photography as a fixer solution to remove unexposed silver halide from photographic prints and negatives.
Questions:
Q: What is the purpose of sodium acetate in amide synthesis?
A: NaC2H3O2 is used in amide synthesis as a base to deprotonate the amine group of the starting material. This facilitates the reaction with the carboxylic acid to form the amide bond.
Q: What is the purpose of the sodium acetate solution in the amide synthesis?
A: The NaC2H3O2 solution is used as a basic catalyst in amide synthesis. It helps to deprotonate the amine group of the starting material, making it more reactive towards the carboxylic acid.
Q: Is sodium acetate a base?
A: Yes, NaC2H3O2 is a base. It is the conjugate base of acetic acid and has a pH of around 9 when dissolved in water.
Q: What is sodium acetate?
A: NaC2H3O2 is a sodium salt of acetic acid, with the chemical formula NaCH3COO. It is a white, odorless, and crystalline powder that is soluble in water.
Q: What is the purpose of the sodium acetate solution in the amide synthesis of acetophenetidin?
A: In the amide synthesis of acetophenetidin, the NaC2H3O2 solution is used as a basic catalyst to facilitate the reaction between p-phenetidine and acetic anhydride. It helps to deprotonate the amine group of p-phenetidine and activate it towards nucleophilic attack by the acetic anhydride. This results in the formation of acetophenetidin.