How to make CARBONATE- BICARBONATE BUFFER?

        ( This is a practical experiment)

How to make CARBONATE- BICARBONATE BUFFER?

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 REAGENTS REQUIRED:

 • Sodium carbonate solution 0.2M: Dissolve 2.12gm of anhydrous sodium carbonate in 100ml Distilled water.

 • Sodium bicarbonate solution: Dissolve 1.68gm of sodium bicarbonate in 100ml of distilled water.

PROCEDURE: 

Pipette out exactly 27.5ml of sodium carbonate (Na2Co3) solution. To this add 22.5ml of sodium bicarbonate solution and made upto 100ml with distilled water which corresponds to 0.2 M sodium carbonate and bicarbonate buffer. Standardise pH meter and measure the pH of required buffer. This gives the Carbonate- bicarbonate buffer pH 10.2. 

RESULT: 

Carbonate bicarbonate buffer was prepared and pH observed was 7.5 which was adjusted to 10.2 using 1N Hcl and 5N NaoH.