Procedure for preparation and standardization 0.1 N Potassium Permanganate

1. OBJECTIVE
To lay down the procedure for preparation and standardization of 0.1 N Potassium Permanganate

2. SCOPE
This procedure is applicable to Quality Control Department

3. RESPONSIBILITY
• Officer QC
• Manager QC

4. SAFETY INSTRUCTIONS
• Proper handling the apparatus.
• It is recommended to wear gloves and protective eyewear when handling chemicals.
• Additionally, it is important to weigh the chemical accurately and dissolve it completely to ensure the desired concentration of the solution.
• Store in glass-stoppered, amber-colored bottles.

5. PROCEDURE
5.1 PREPARATION
5.1.1 Calculate the amount of Potassium Permanganate needed to prepare a 0.1 N solution by using the formula:
      grams of Potassium Permanganate = M x V (L) x EW

where M is the desired morality,can be calculated by dividing the normality of the solution by by the number of no.of electrons gained in redox reation, which is 5 for KMnO4, V is the volume of the solution to be prepared, and EW is the equivalent weight of Potassium Dichromate.

The equivalent weight of Potassium Permanganate is 31.61 g/equivalent (since To find equivalent weight of potassium dicromate, we must go through the change of oxidation state i.e no.of electrons gained in redox reation which is 5 for KMnO4) the equivalent weight of Potassium Permanganate =158.03/5=31.606).

      grams of Potassium Permanganate = 0.1 x 1 x 31.606 = 3.161 g

5.1.2 Weigh out 3.161gm of Potassium Permanganate using a balance.
5.1.3 After measuring the required amount, transfer it into a 1 liter volumetric flask.
5.1.4 Add a small amount of distilled water to the flask and swirl to dissolve.
5.1.5 Then fill up the flask with distilled water until the mark and boil the solution for about 15 minutes. 5.1.6 Insert the stopper in the flask, allow it to stand for at least 2 days, and filter through a fine-porosity, sintered-glass crucible.
5.1.7 If necessary, the bottom of the sintered-glass crucible may be lined with a pledget of glass wool. .
5.2 STANDARDIZATION
5.2.1 Accurately weigh about 200 mg of sodium oxalate, previously dried at 110 to constant weight, and dissolve it in 250 mL of water.
5.2.2 Add 7 mL of sulfuric acid, heat to about 70, and then slowly add the permanganate solution from a buret, with constant stirring, until a pale pink color, which persists for 15 seconds, is produced.
5.2.3 The temperature at the conclusion of the titration should be not less than 60. Calculate the normality.
5.2.4 Each 6.700 mg of sodium oxalate is equivalent to 1 mL of 0.1 N potassium permanganate.
5.2.5 Since potassium permanganate is reduced on contact with organic substances such as rubber, the solution must be handled in apparatus entirely of glass or other suitably inert material. It should be frequently restandardized.
5.2.6 And calculate the normality by the following formula:

         g Na₂C₂O₄
N= ————————————–
         ml of KMnO₄ solution x 0.06700

6. RELATED DOCUMENTS
N/A

7. DISTRIBUTION INDEX
Original Copy will be retained by Quality Assurance Department.

8. ABBREVIATIONS
Q.C Quality Control Department
TS Test Solution
Gm Gram
ml Milliliter

9. REVISION HISTORY