Acetic Acid-Sodium Acetate and Carbonate-Bicarbonate Buffers

Prepare a solution by mixing 1.5 ml of glacial acetic acid with 100 ml of distilled water.
Dissolve 0.64 g of sodium acetate or 2.72 g of sodium acetate trihydrate in 100 ml of distilled water.
Pipette out exactly 36.2 ml of the sodium acetate solution into a 100 ml standard flask.
Add 14.8 ml of glacial acetic acid to this flask and make the volume up to 100 ml with distilled water.
This preparation results in a buffer comprising 0.2 M acetic acid and sodium acetate.
Measure the pH using a pH meter.

Dissolve 2.12 g of anhydrous sodium carbonate in 100 ml of distilled water to form a sodium carbonate solution.
Prepare a sodium bicarbonate solution by dissolving 1.68 g of sodium bicarbonate in 100 ml of distilled water.
Pipette out exactly 27.5 ml of the sodium carbonate solution.
Add 22.5 ml of the sodium bicarbonate solution to the 27.5 ml sodium carbonate solution.
Make up the total volume to 100 ml with distilled water. This results in a buffer corresponding to 0.2 M of sodium carbonate and bicarbonate.
Standardize the pH meter and measure the pH of the prepared buffer.

Volume of glacial acetic acid used: 1.5 ml (diluted to 100 ml with distilled water).
Sodium Acetate used: 0.63479 g (also diluted to 100 ml with distilled water).
Preparation: 36.2 ml of sodium acetate solution combined with 14.8 ml of glacial acetic acid solution, then completed to 100 ml with distilled water.
Measured pH: 5.24, with an expected pH of 4.00.
Accuracy Test:
- Expected pH = 4.00
- Observed pH = 4.85.

Sodium Bicarbonate Used: 1.6819 g
Anhydrous Sodium Carbonate Used: 2.1240 g.
Preparation: 27.5 ml sodium carbonate solution combined with 22.5 ml sodium bicarbonate solution, then completed to 100 ml with distilled water.
Observed pH: 10.29.