3M Sodium Acetate (CH3COONa)

3M Sodium Acetate (CH3COONa) Preparation Protocol at pH 4.8

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1. Purpose:

This protocol guides the preparation of a 3M Sodium Acetate (CH3COONa) solution with a pH of 4.8, commonly used in various laboratory applications.

2. Materials:

• Chemicals:
  • Sodium Acetate Trihydrate (CH3COONa·3H2O)
  • Concentrated Acetic acid (CH3COOH)
  • H2O (Water)
• Equipment:
  • Weighing scale
  • pH meter
  • Autoclave
• Personal Protective Equipment (PPE):
  • Lab coat
  • Gloves
  • Safety glasses

3. Procedure:

1. Preparation of Sodium Acetate (CH3COONa): Weigh 408.1 g of Sodium Acetate Trihydrate (CH3COONa·3H2O) using an appropriate weighing scale.
2. ** Dissolution: ** Add the sodium acetate to less than 500 ml of water. Note that it takes a large amount of Acetic acid (CH3COOH) to adjust the pH, so start with a smaller volume of water.
3. pH Adjustment: Use concentrated Acetic acid (CH3COOH) to adjust the pH of the solution to 4.8. Continue adding Acetic acid to the solution until the desired pH is achieved.
4. Volume Adjustment to Make 3M Solution: Add more water until the final volume is 1 litre. 408.1 g in 1 litre of solution gives a concentration approximately equal to 3M.
5. Sterilization: Autoclave the solution to achieve sterility. This should be done at 121°C for 15 minutes.

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