Potassium Permanganate Formula, Structure, Properties, Uses

Potassium Permanganate Formula: Potassium (K) is an elemental substance with an atomic number of 19 on the periodic table. It appears as a soft, silvery-white metal that can be cut with a knife with relative ease. When exposed to oxygen, it undergoes a reaction, resulting in the formation of flaky white potassium peroxide.

Permanganate, on the other hand, is a chemical compound that comprises the manganate(VII) ion, denoted as MnO⁻₄, which serves as the conjugate base of permanganic acid. This compound is known for its remarkable oxidizing properties due to the manganese atom within it being in a +7 oxidation state.

Potassium Permanganate Formula

Potassium Permanganate, as an inorganic chemical compound, consists of two primary ions: the Permanganate ion (MnO⁻₄) and the potassium ion (K⁺). It presents itself as a dark purple, odorless solid, and when dissolved in water, it imparts a purple color to the resulting solution. It is a recognized potent oxidizing agent that generates non-toxic byproducts, and it is commonly synthesized from minerals containing manganese oxide.

Potassium Permanganate Formula Structure

Potassium permanganate is characterized by an ionic bond between the potassium cation and the permanganate anion.

Preparation of Potassium Permanganate

Potassium permanganate is synthesized through a process that involves mixing a solution of KOH (potassium hydroxide) and powdered manganese oxide along with oxidizing agents like potassium chlorate. The resulting mixture is then subjected to boiling and evaporation, with the residue subsequently heated in iron pans until it reaches a pasty consistency. The chemical equation for this process is:

6KOH + 3MnO ₂ + 6KClO ₃ → 3K ₂ MnO ₄ + 6KCl + 3H ₂ O

The potassium manganate (K2MnO4) produced in this step is further processed by boiling it with water and introducing chlorine while passing ozonized air into the liquid until it transforms into potassium permanganate:

6K ₂ MnO ₄ + 3Cl ₂ → 6KMnO ₄ + 6KCl.

Potassium Permanganate Formula Physical Properties

Molecular Weight: 158.034 g/mol

Density: 2.703 g/cm³

Boiling Point: 100°C

Melting Point: 240°C

Oxidation State: +7

Appearance: Odorless purple crystalline solid

Solubility: Potassium permanganate is soluble in water, with increased solubility in boiling water. It can also dissolve in acetone, acetic acid, methanol, pyridine, ethanol, and various organic compounds.

Taste: It has a slightly acidic or bitter taste.

Potassium Permanganate Formula Chemical Properties

Thermal Decomposition:

When subjected to heat, potassium permanganate undergoes thermal decomposition, resulting in the formation of other compounds:

2KMnO ₄ → K ₂ MnO ₄ + MnO ₂ + O ₂

Reaction with Acid:

Potassium permanganate reacts with concentrated hydrochloric acid, producing chlorine gas. During this reaction, potassium permanganate is reduced to form an alkaline solution, and it transforms into green K2MnO4:

2KMnO ₄ + 16HCl → 2KCl + 2MnCl ₂ + 5H ₂ O + 8Cl ₂

Interaction with Alkalis:

When potassium permanganate is heated in the presence of alkalis, it transforms into manganate, accompanied by the evolution of oxygen gas:

4KMnO ₄ + 4KOH → 4K ₂ MnO ₄ + 2H ₂ O + O ₂

Oxidizing Properties:

Potassium permanganate (KMnO4) is a potent oxidizing agent, exhibiting its oxidizing abilities in acidic, neutral, and alkaline environments. The oxidation reactions are as follows:

In an acidic medium:

1. 2KMnO ₄ + H ₂ SO ₄ → K ₂ SO ₄ + 2MnSO ₄ + 3H ₂ O + 5[O]
2. MnO ^– ₄ + 8H+ + 5e ^– → Mn ₂ + + 4H ₂ O

In a neutral or alkaline medium:

1. 2KMnO ₄ + H ₂ O → 2KOH + 2MnO ₂ + 3[O]
2. MnO ^– ₄ + 2H ₂ O + 3e ^– → MnO ₂ + 4OH ^–

Uses Potassium Permanganate

• Assessment of Permanganate Value: Potassium permanganate is used for determining the permanganate value in various chemical analyses.
• Water Treatment: It finds use as an in-well water treatment agent to eliminate hydrogen sulfide and iron contaminants, thus improving water quality.
• Disinfectant: Potassium permanganate serves as a disinfectant, effectively treating specific skin conditions such as fungal infections and dermatitis.
• Medicinal Uses: This compound is utilized in the treatment of bacterial infections, contributing to its role in healthcare.
• Industrial Applications: Industries like leather tanning and fabric printing make use of potassium permanganate in their processes to achieve desired outcomes.