What is the Difference Between Potassium Permanganate and Potassium Manganate

The key difference between potassium permanganate and potassium manganate is that potassium permanganate appears as purple-bronze needle-shaped crystals, whereas potassium manganate appears as green crystals.

Potassium permanganate and potassium manganate are often confused due to their nearly similar names and appearances. However, they are different in chemical and physical properties.

CONTENTS

1. Overview and Key Difference
2. What is Potassium Permanganate
3. What is Potassium Manganate 
4. Potassium Permanganate vs Potassium Manganate in Tabular Form
5. Summary – Potassium Permanganate vs Potassium Manganate 

What is Potassium Permanganate?

Potassium permanganate is an inorganic compound having the chemical formula KMnO₄. It is an ionic compound (a salt of potassium) containing a potassium cation in combination with a manganite anion. This compound is a strong oxidizing agent. This is because it can undergo reduction through the manganese atom in the anion; manganese in this compound is in a +7 oxidation state, which is the highest oxidation state it can reside in. Therefore, it can be easily reduced into lower oxidation states by oxidizing other oxidizable compounds.

Potassium permanganate occurs in the solid-state at room temperature. It appears like needle-like structures that are dark purple in colour. It is highly water-soluble, and when dissolved, it forms a dark purple coloured solution. We can produce potassium permanganate industrially through the fusion of manganese oxide with potassium hydroxide, followed by heating in the air.

There are many uses of potassium permanganate in different areas such as medical uses, water treatment, synthesis of organic compounds, analytical uses such as titrations, fruit preservation, included in survival kits as a hypergolic fire starter, etc.

What is Potassium Manganate?

Potassium manganate is an inorganic compound having the chemical formula K2MNO4. It occurs as a green coloured salt compound that can be found as an intermediate in the industrial synthesis of potassium permanganate.

This chemical compound contains potassium cations and manganate anions, and the anion is a tetrahedral ion in which the Mn-O bond is longer than the Mn-O bond in potassium permanganate. Moreover, this compound is isostructural with potassium sulfate.

We can synthesize potassium manganate through the treatment of MnO2 with air. It gives a green-coloured melt. As an alternative method, we can use potassium nitrate as an oxidizer instead of air. However, on a laboratory scale, we can produce potassium manganate by heating a solution of potassium permanganate in the presence of a concentrated KOH solution followed by cooling, which gives green crystals.

Difference Between Potassium Permanganate and Potassium Manganate

Potassium permanganate is an inorganic compound having the chemical formula KMnO_4, while potassium manganate is an inorganic compound having the chemical formula K2MNO4. The key difference between potassium permanganate and potassium manganate is that potassium permanganate appears as purple-bronze needle-shaped crystals, whereas potassium manganate appears as green crystals.

Moreover, potassium permanganate is an orthorhombic crystal while potassium manganate is isomorphous with K2SO4. In addition to these differences, potassium permanganate is formed from manganese dioxide, whereas potassium manganate is produced through the treatment of MnO2 with air.

The below infographic lists the differences between potassium permanganate and potassium manganate in tabular form for side by side comparison.

Summary – Potassium Permanganate vs Potassium Manganate

Potassium permanganate is an inorganic compound having the chemical formula KMnO_4, while Potassium manganate is an inorganic compound having the chemical formula K2MNO4. The key difference between potassium permanganate and potassium manganate is that potassium permanganate appears as purple-bronze needle-shaped crystals, whereas potassium manganate appears as green crystals.

Reference:

1. “Potassium Manganate.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.

Image Courtesy:

1. “Potassium Manganate” By Саня Ардент – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Potassium-permanganate-sample” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia