Sodium Acetate (CH₃COONa) is the sodium salt of acetic acid. It appears as a white crystalline powder, either odorless or with a faint vinegar-like smell (especially when heated). Sodium acetate is slightly hygroscopic, particularly in its anhydrous form, and exists in two common forms:

• Anhydrous (dry) sodium acetate, and

• Hydrated sodium acetate, typically the trihydrate form (CH₃COONa·3H₂O).

Chemical Structure of Sodium Acetate

Sodium acetate is an ionic compound composed of a sodium cation (Na⁺) and an acetate anion (CH₃COO⁻).
The acetate ion contains a methyl group (CH₃) bonded to a carboxylate group (COO⁻). Within the carboxylate group, the double bond between carbon and oxygen exhibits resonance, meaning the negative charge is delocalized over both oxygen atoms.

Chemical formula: CH₃COONa
Resonance structure: O=C–O⁻ ↔ ⁻O–C=O

Properties of Sodium Acetate

Applications of Sodium Acetate

1. Food Industry

• Used as a food additive (E262) for pH control, flavoring (salty/sour), and preservation.

• Exhibits antibacterial and antifungal properties in certain food formulations.

2. Pharmaceutical and Medical Applications

• Used as a source of sodium in IV infusions and dialysis solutions.

• Functions as a buffering agent in pharmaceutical formulations and biological reactions.

3. Textile Industry

• Serves as a dyeing assistant and pH regulator in dye baths.

• Neutralizes residual acids such as sulfuric acid (H₂SO₄).

• Helps prevent static electricity on fabrics.

4. Construction Industry

• Used as an additive in concrete to control pH and improve frost resistance (acts as a sealing agent).

5. Laboratory Applications

• Widely used in buffer preparation (especially in biochemistry and DNA extraction).

• Acts as a carbon source for bacterial cultures.

• Included in extraction and purification solutions in molecular biology.

6. Hand Warmers and Heat Packs

• In supersaturated sodium acetate trihydrate solutions, rapid crystallization releases latent heat (approximately 264–289 kJ/kg)—used in reusable heating pads.

7. Other Industrial Uses

• Rubber industry: delays vulcanization of chloroprene.

• Leather tanning and dye production: acts as a process regulator.

Advantages of Sodium Acetate

✅ FDA-approved as safe for food use (within regulated limits)
✅ Effective buffering properties
✅ High compatibility with industrial processes
✅ Low cost and readily available
✅ Exhibits antimicrobial and preservative effects
✅ Useful in phase-change thermal systems

Disadvantages of Sodium Acetate

⚠️ Hygroscopic (especially the anhydrous form) — requires sealed storage
⚠️ Irritating to eyes and skin upon contact
⚠️ Inhalation of dust may cause respiratory irritation
⚠️ Ingestion in excess may lead to gastrointestinal discomfort or hypernatremia
⚠️ Decomposes at high temperatures, releasing irritating vapors
⚠️ Should be used with caution in renal or cardiac patients due to electrolyte effects
⚠️ Some pharmaceutical forms may contain aluminum or other excipients, requiring special care in premature infants or renal patients

Calcium Diacetate is a chemical compound with the formula Ca(CH₃COO)₂. It is found as a white crystalline powder and is usually odorless or has a faint vinegar-like smell. Other names include calcium acetate and calcium ethanoate. The anhydrous form is very hygroscopic, so it is commonly supplied as the monohydrate (Ca(CH₃COO)₂·H₂O).

Structure of Calcium Diacetate

A molecule of calcium diacetate consists of one Ca²⁺ cation and two acetate anions (CH₃COO⁻). The calcium ion serves as the central cation, ionically bonded to two negatively charged acetate groups. Its crystalline structure varies depending on hydration.

Key Properties of Calcium Diacetate

• Appearance: White crystalline powder

• Odor: Generally odorless, or faint vinegar smell

• Solubility: Freely soluble in water; slightly soluble in methanol; insoluble in acetone, ethanol, and benzene

• Molar Mass: Approximately 158.17 g/mol (anhydrous)

• Melting/Decomposition Point: Decomposes around 160 °C

• Density: About 1.509 g/cm³

• pH of Aqueous Solution: Neutral to slightly alkaline (pH ~6.3–9.6 for 10% solutions)

• Hygroscopicity: The anhydrous form strongly absorbs moisture

Advantages of Calcium Diacetate

• Source of Calcium: Used in dietary and pharmaceutical supplements

• Food Preservative: Added under E263, inhibits mold growth and extends shelf life of baked goods

• pH Regulator: Acts as a buffering agent in food processing

• Stabilizer: Used in textile dyeing for color fixation and in food like canned vegetables and tofu to improve texture

• Generally Recognized as Safe: Considered non-toxic at permitted levels

• Good Water Solubility: Facilitates incorporation in various formulations

Disadvantages of Calcium Diacetate

• Digestive Side Effects: Overconsumption or sensitivity may cause mild GI symptoms like bloating, constipation, or gas

• Hygroscopic Nature: Needs dry storage to prevent moisture absorption

• Drug Interactions: May interfere with absorption of certain medications—consultation advised when taken concurrently

• Risk of Hypercalcemia: Excessive intake can raise blood calcium levels, leading to related health risks

Applications of Calcium Diacetate

Food Industry:

• Preservative (anti-mold) in breads, pastries, and other baked goods

• pH regulator and buffer

• Stabilizer/firming agent in foods such as tofu (as a preferred alternative to calcium sulfate) and canned vegetables

• Ingredient in candies, desserts, puddings

• Additive in animal feed

Pharmaceutical Sector:

• Buffering agent in medicinal formulations

• Calcium supplement for deficiency

• Phosphate binder for dialysis patients with high blood phosphate

Textile Industry:

• Used as a color fixer

Chemical Industry:

• Catalyst in select chemical reactions

• Previously used in acetone production

Wastewater Treatment:

• Employed to remove phosphate from wastewater

Soap Production:

• Utilized as an alkali in certain soap manufacturing

Fire Gel Production:

• When dissolved in alcohol at saturation, it forms a semi-solid, combustible gel suitable for flame use