Procedure for preparation and standardization 0.1 N Perchloric Acid

1. OBJECTIVE
To lay down the procedure for preparation and standardization of 0.1 N Perchloric Acid

2. SCOPE
This procedure is applicable to Quality Control Department

3. RESPONSIBILITY
• Officer QC
• Manager QC

4. SAFETY INSTRUCTIONS
• Proper handling the apparatus.
• Remember to handle concentrated hydrochloric acid with care as it is highly corrosive and can cause severe burns.
• Wear appropriate protective gear, such as gloves and eye protection, and work in a well-ventilated area.

5. PROCEDURE
5.1 PREPARATION
5.1.1 Determine the molarity of the Perchloric Acid (70%) solution you have. The density and %age of Perchloric Acid is typically listed on the bottle or container.
5.1.2 Calculate the amount of concentrated Perchloric Acid solution you will need to make 1 liter of 0.1N Perchloric Acid solution. To do this, you can use the following formula:
Stock bottle of 70% Perchloric Acid.
Determination of molarity of 70% Perchloric Acid V/V
As Molarity = % by weight x 10 x density x 1000/ mol. weight
Put the values
      Molarity = 70 x 10 x 1.68 / 100.46 = 11.70 ~ 12M

      Compounding 1 liter of 1N Solution
      M1V1 = M2V2
      (0.1)(1000) = (12) (x)

      x = (0.1) (1000) / 12
      x = 8.3 ml

Therefore add 8.3 ml of 70% Perchloric Acid to 1 liter
5.1.4 Measure out the calculated amount of concentrated Perchloric Acid solution using a graduated cylinder or pipette.
5.1.5 Mix 8.5 mL of perchloric acid with 500 mL of glacial acetic acid and 21 mL of acetic anhydride, cool, and add glacial acetic acid to make 1000 mL. .
5.1.6 Allow the prepared solution to stand for 1 day for the excess acetic anhydride to be combined
5.2 STANDARDIZATION
5.2.1 Accurately weigh about 700 mg of potassium biphthalate, previously crushed lightly and dried at 120 for 2 hours, and dissolve it in 50 mL of glacial acetic acid in a 250-mL flask.
5.2.2 Add 2 drops of crystal violet TS, and titrate with the perchloric acid solution until the violet color changes to blue-green.
5.2.3 Deduct the volume of the perchloric acid consumed by 50 mL of the glacial acetic acid. Each 20.42 mg of potassium biphthalate is equivalent to 1 mL of 0.1 N perchloric acid.
5.2.4 And calculate the normality by the following formula:

         gm KHC₈H₄O₄
N= ————————————————–
         0.20423 x ml HCLO₄ solution (corrected for blank)

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