Monday, March 13, 2023

Preparation of KMnO4 solution

Learn how to make different concentrations of molar and normal potassium permanganate solutions, which are needed for many applications such as research, practical, pharmaceutical, chemical laboratory, and industries, etc.

In 1659, a German-Dutch scientist named Johann Rudolf Glauber was the first to find out that KMnO4 could be produced. Potassium permanganate is a manganese-based chemical compound derived from manganese dioxide. It does not occur naturally in its pure form but is present in many types of rocks in conjunction with oxygen, sulphur, and chlorine. It decomposes into oxygen when heated alone or with an alkali.

Potassium permanganate has the chemical formula KMnO4 and is an inorganic compound. It is a crystallized salt that has a purplish-black color, and when dissolved in water, it forms a solution that is highly pink to purple. It has many uses in the laboratory and chemical industry, as well as being used for the treatment of dermatitis, as a wound cleaner, and for disinfectant purposes.

Generally, a solid form of potassium permanganate (KMnO4) is supplied in different-sized packs is supplied in the market by vendors in the form of a purplish-colored, crystalline solid powder.
  • The molecular weight of KMnO4 is 158.034 g/mol
  • The melting point of KMnO4 is 240 °C
  • The density of KMnO4 is 2.7 g/cm
  • The solubility of KMnO4 is soluble in water, acetone, methanol, pyridine, etc.


Requirements of glassware, chemicals, and apparatus:

Digital balance, beaker, pipette, pipette bulb, volumetric flask, measuring cylinder, glass rod, funnel, distilled water, AR/LR grade potassium permanganate (KMnO4), etc.

Calculation method:

For example, we calculate how much weight of solid potassium permanganate is needed to prepare a 0.1M solution in a 500 ml flask.

Let's first determine the molar mass (m) of KMnO4

K has a molecule weight of 40. The molecular weight of Mn is 54, and that of oxygen is 16. Here,
{{O} _ {4}} = 16X4=64
Thus, total – 40+54+64=158g
We have been given that, V = 500 ml, m = 158 g, M = 0.1M

The following equation can be used to determine the molarity of a given solution:
Molarity=W/m×1000/V
Rearranging this equation to account for the weight necessary gives us,
W =Molarity × m × V/ 1000
Putting the given values in this equation,
W=0.1×158×500/1000 =7.9 gm
Therefore, to make a 0.1 N solution of KMnO4, dilute 7.9 gm of KMnO4 in 500 ml of distilled water.

prepare kmno4 solution

How to prepare 0.02M KMnO4 solution?

Weigh accurately 03.16 g of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare a 0.05M KMnO4 solution?

Weigh accurately 7.9 gm of potassium permanganate and dissolve in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water and properly mix it.

How to prepare 0.1M KMnO4 solution?

Weigh accurately 15.80 gm of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.2M KMnO4 solution?

Weigh accurately 31.60 gm of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water and properly mix it.

How to prepare 0.25 molar potassium permanganate solution?

Weigh accurately 19.75 gm of KMnO4 and dissolve in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 500 ml with distilled water, and properly mix it.

How to prepare 0.5M KMnO4 solution?

Weigh accurately 79.00 gm of KMnO4 and dissolve in 400 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 1M KMnO4 solution?

Weigh accurately 15.8 g of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 2M potassium permanganate solution?

Weigh accurately 79.00 gm of KMnO4 and dissolve in 100 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 250 ml with distilled water, and properly mix it.

How do you make a 1% solution of KMnO4?

Weigh accurately 1.00 g of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 2% KMnO4 solution?

Weigh accurately 02.00 gm of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 5% potassium permanganate solution?

Weigh accurately 05.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 7% KMnO4 solution?

Weigh accurately 07.00 gm of potassium permanganate solid powder and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 10% potassium permanganate solution?

Weigh accurately 10.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 20% solution of Potassium permanganate?

Weigh accurately 20.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare a 100 ppm solution of KMnO4?

To make a 100 ppm stock solution, mix 10 mg of potassium permanganate with 100 ml of distilled water in a volumetric flask.

How do you make a 1 ppm solution of KMnO4?

Take 0.1 ml (100 microliters) of a 100 ppm stock solution and dilute it to 10 ml; the resulting solution has a concentration of 1 ppm.

How to prepare a 10 ppm solution of KMnO4?

Take 1 ml of a 100 ppm stock solution of potassium permangnate and dilute it to 10 ml; the resulting solution has a concentration of 1 ppm.


PRECAUTIONS:
  • KMnO4 is hygroscopic in nature it should be stored in a tightly closed container.
  • Stir a little amount of potassium permanganate into a large volume of water at a time, and then dilute the solution.
  • When making potassium permanganate solutions, it is recommended that always use distilled water.
  • Wear protective gloves, clothing, eye protection, and face protection.
  • Wash your hands/skin thoroughly after handling.
  • Chemical contact can cause serious skin and eye irritation. Therefore should be handled with care, follow laboratory safety measures (SOP/Procedure), and please use extreme caution when preparing the solution concentrations.

References:
  1. Indian Pharmacopoeia : 1996
  2. Wikipedia contributors. (2022, July 1). potassium_permanganate. In Wikipedia, The Free Encyclopedia. Available Here:
  3. What Is the Difference between Molarity and Normality? Westlab. Available Here:
  4. Making Percent Solutions Of Chemicals, Available Here:

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