What Is Potassium Acetate?
Potassium acetate is a potassium salt of acetic acid.
Its molecular formula is CH3COOK, and its molecular weight is 98.14. It is produced through the neutralization reaction of acetic acid with potassium hydroxide or potassium carbonate. At room temperature, it appears as a colorless or white crystalline powder.
Potassium acetate is deliquescent; thus, it requires careful storage. It may react violently with strong oxidizers or decompose upon contact with strong acids. However, potassium acetate is not regulated under the poisonous substances control or safety and fire laws.
Uses of Potassium Acetate
Potassium acetate serves various purposes in pharmaceuticals, as an anti-freeze, and as a research reagent.
1. Pharmaceuticals
Following diarrhea, vomiting, or surgery, the body may experience potassium deficiency. Potassium acetate is used in pharmaceuticals to replenish such deficiencies. It plays a role in regulating heart and muscle functions due to the potassium ions.
2. Anti-freeze Agent
As an anti-freeze agent, potassium acetate is advantageous because it is not corrosive to metals, unlike sodium chloride-based agents, and is biodegradable. It is thus considered an environmentally friendly solution for preventing ice formation on road surfaces.
3. Research Reagent
In molecular biology, a mixture of potassium acetate and acetic acid, pH-adjusted to around 5, is utilized for plasmid DNA extraction, facilitating the separation of desired plasmid DNA from other materials.
Besides, potassium acetate is employed in a wide array of applications including as an analytical reagent, dehydrating agent, fire extinguishing agent, and raw material for organic synthesis.
Properties of Potassium Acetate
Potassium acetate emits a slight acetic acid odor and has a specific gravity of 1.6 g/cm3. It melts at 292°C. Being a salt derived from a weak acid (acetic acid) and a strong base (potassium hydroxide), it ionizes in water to produce acetate ions and potassium ions.
CH3COOK → CH3COO– + K+
In aqueous solutions, acetate ions react with hydrogen ions, leading to a slightly basic solution (pH 7.5 to 9.0). This is because acetate ions can combine with hydrogen ions from water ionization, forming acetic acid and shifting the solution to a more basic pH.
Potassium acetate dissolves well in water—256 grams per 100 grams of water at 20°C—and is also soluble in ethanol (C2H5OH).
Types of Potassium Acetate
Available in various grades, including reagent grade and grade 1, potassium acetate is sold in quantities of 25 g, 500 g, and 20 kg. Solutions for industrial use are available in 25 kg and 250 kg containers.
Other Information on Potassium Acetate
1. Synthesis of Potassium Acetate
Reaction of potassium acetate with potassium hydroxide
CH3COOH + KOH → CH3COOK + H2O
Reaction of potassium acetate and potassium carbonate
2CH3COOH + K2CO3 → 2CH3COOK + CO2 + H2O
2. Reaction With Strong Oxidizers
Reaction of potassium acetate with potassium permanganate
14CH3COOK + 16KMnO4 → 16Mn + 15K2CO3 + 13CO2 + 21H2O
3. Reaction With Strong Acids
Reaction of potassium acetate with hydrogen chloride
CH3COOK + HCl → KCl + CH3COOH
Reaction of potassium acetate with hydrogen iodide
CH3COOK + HI → KI + CH3COOH
4. Decomposition Reaction
Formation of acetic acid
2CH3COOK → 2KOH + CH3COOH + 2C