Procedure for preparation and standardization 0.1 N Ferric Ammonium Sulfate

1. OBJECTIVE
To lay down the procedure for preparation and standardization of 0.1 N Ferric Ammonium Sulfate

2. SCOPE
This procedure is applicable to Quality Control Department

3. RESPONSIBILITY
• Officer QC
• Manager QC

4. SAFETY INSTRUCTIONS
• Proper handling the apparatus.
• Always wear appropriate personal protective equipment when handling this chemical.
Always handle the chemicals with care and dispose of any waste properly.
Store in tight containers, protected from light.

5. PROCEDURE
5.1 PREPARATION
5.1.1 Determine the molecular weight of ferric ammonium sulfate. The molecular weight of Ferric Ammonium Sulfate is 482.19 g/mol.
5.1.2 Calculate the amount of Ferric Ammonium Sulfate needed to prepare the solution. To prepare a 0.1N solution, you will need 0.1 moles of Ferric Ammonium Sulfate per liter of solution. Therefore, to prepare 1 liter of solution, you will need:
0.1 moles/L x 1 L = 0.1 moles
5.1.3 The mass of Ferric Ammonium Sulfate required can be calculated using the following formula:
Mass (g) = moles x molecular weight (g/mol)
Mass (g) = 0.1 moles x 482.19 g/mol
Mass (g) = 48.22 gm
5.1.4 Weigh out 48.22gm of Ferric Ammonium Sulfate using a balance.
5.1.5 After measuring the required amount, transfer it into a 1 liter volumetric flask containing mixture of 300ml of water and 6ml of sulfuric acid and swirl to dissolve.
5.1.6 Then fill up the flask with distilled water until the mark and mix well.
5.2 STANDARDIZATION
5.2.1 Accurately measure about 40 mL of the solution into a glass-stoppered flask, add 5 mL of hydrochloric acid, mix, and add a solution of 3 g of potassium iodide in 10 mL of water.
5.2.2 Insert the stopper, allow to stand for 10 minutes, then titrate the liberated iodine with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached.
5.2.3 Correct for a blank run on the same quantities of the same reagents.
5.2.4 And calculate the normality by the following formula:
ml Na₂S₂O₃ x N Na₂S₂O₃
N= ————————————————————————————————
ml FeNH₄ (SO₄)₂

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