Procedure for preparation and standardization of 0.1N Bromine Solution

1. OBJECTIVE
To lay down the procedure for preparation and standardization of 0.1N Bromine Solution

2. SCOPE
This procedure is applicable to Quality Control Department

3. RESPONSIBILITY
• Officer QC
• Manager QC

4. SAFETY INSTRUCTIONS
• Proper handling the apparatus.
• Proper handling the chemicals
• Bromine is a highly reactive and toxic substance. It should be handled with extreme caution, and appropriate safety measures (such as gloves, goggles, and a fume hood) should be taken to avoid contact with the skin, eyes, or respiratory system.
• Preserve in dark amber-colored, glass-stoppered bottles

5. PROCEDURE
5.1 PREPARATION
Method I:
5.1.1 To prepare a 0.1N solution of bromine, you will need to use the following formula:
Weight = (N x V x 80) / 1000
Where:
N = Normality of the solution (0.1N)
V = Volume of the solution you want to prepare (1 liter)
80 = Molecular weight of bromine
1000 = Density of water
Substituting the values, we get:
Weight = (0.1N x 1L x 80) / 1000
Weight = 8 grams
5.1.2 Therefore, you will need to measure 8 grams of bromine using a chemical balance.
5.1.3 After measuring the required amount of bromine, you will need to 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 the bromine.
5.1.5 Then fill up the flask with distilled water until the mark and mix well.
Method II:
Bromine (Bromide-Bromate), 0.1N Volumetric Solution:
5.1.6 Calculation of the amount of Potassium Bromate and Potassium Bromite needed, the amount of potassium bromate (KBrO3) and potassium bromite (KBrO2) required to prepare the 0.1N solution of bromine can be calculated as follows:
Weight of KBrO3 = (N x V x 167) / 1000
Weight of KBrO2 = (N x V x 199) / 1000

Where:
N = Normality of the solution (0.1N)
V = Volume of the solution you want to prepare (1 liter)
167 = Molecular weight of KBrO3
199 = Molecular weight of KBrO2
1000 = Density of water
Substituting the values, we get:

Weight of KBrO3 = (0.1N x 1L x 167) / 1000
Weight of KBrO3 = 16.7 grams
Weight of KBrO2 = (0.1N x 1L x 199) / 1000
Weight of KBrO2 = 19.9 grams

5.1.7 Therefore, you will need to measure 16.7 grams of KBrO3 and 19.9 grams of KBrO2 using a chemical balance.
5.1.8 After measuring the required amount of KBrO3 and KBrO2, you will need to transfer them into a 1 liter volumetric flask.
5.1.9 Add a small amount of distilled water to the flask and swirl to dissolve the salts.
5.1.10 Then fill up the flask with distilled water until the mark and mix well.
5.2 STANDARDIZATION
5.2.1 Accurately measure about 25 mL of the solution into a 500-mL iodine flask, and dilute with 120 mL of water.
5.2.2 Add 5 mL of hydrochloric acid, insert the stopper in the flask, and shake it gently.
5.2.3 Then add 5 mL of potassium iodide TS, again insert the stopper, shake the mixture, allow it to stand for 5 minutes.
5.2.4 And titrate the liberated iodine with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached.

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
Vs. Against
Gm Gram
ml Millilitre

9. REVISION HISTORY