Procedure for preparation and standardization 1 N Sulfuric Acid

1. OBJECTIVE
To lay down the procedure for preparation and standardization of 1 N Sulfuric Acidodium

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
• Always wear appropriate personal protective equipment when handling this chemical.
• Always add the acid (or base) to water, in that order. Pour slowly with constant mixing. This will help prevent rapid heat generation and spattering of the mixture

5. PROCEDURE
5.1 PREPARATION
5.1.1 To make 1000 mL of a 1 N H2SO4 solution, determine the milliliters of concentrated sulfuric acid needed to make 1000 mL of a 1 N solution
5.1.2 You will first need to calculate the equivalent mass of H2SO4. This is the gram-formula weight divided by the number of acid hydrogens in the compound. It is 98/2 = 49.
5.1.3 Then you can calculate the amount of grams of H2SO4 that are needed.
The formula to calculate this is:
      Grams of compound needed = (N desired)(equivalent mass)(volume in liters desired).
      Substituting the above numbers into the equation, we get:
      grams of compound needed = (1 N)(49)(1 liters) = 49 grams.

5.1.4 A 1 N solution requires 49 g of a pure sulfuric acid powder to make 1000ml.
5.1.5 But the acid is a liquid and it is not one hundred percent pure active sulfuric acid. You will need to calculate what volume of the concentrated acid that contains 49 grams of sulfuric acid. The formula for this is:
      Volume of concentrated acid needed = (grams of acid needed)/(percent concentration x specific gravity)
Continuing with the sulfuric acid, plug into the formula the percent concentration and specific gravity from the label on the acid container.
      volume of concentrated acid needed = (49 grams)/(0.97 x 1.84) = 27.46 mL
5.1.6 So take 27.46 mL of concentrated sulfuric acid and diluted it to 1000 mL, you would have a 1 N H2SO4 solution.
5.2 STANDARDIZATION
5.2.1 Accurately weigh about 5.0 g of tromethamine, previously dried at 105 for 3 hours.
5.2.2 Dissolve in 50 mL of water, and add 2 drops of bromocresol green TS. Titrate with 1 N Sulfuric Acid to a pale yellow endpoint.
5.2.3 Each 121.14 mg of tromethamine is equivalent to 1 mL of 1 N Sulfuric Acid.
5.2.4 And calculate the normality by the following formula:

         mg tromethamine
N= ————————————-
         121.14 x ml of H₂SO₄

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