Question

Preparation of buffer solution of acetic acid and sodium acetate and determination of ph

Answer 1

DATE:
AIM:
PREPARATION OF BUFFER
To prepare the buffer at required pH.
PRINCIPLE:
The pH meter measures at electrical potential developed by pair of electrode pins in a solution. For measurement of pH, an electrode system sensitive to change in H+ ion concentration of solution is taken. The electrode system consists of sequence of electrode whose potential raise with pH (H+ concentration of the solution).
PROCEDURE:
1. ACETIC ACID- SODIUM ACETATE BUFFER:
REAGENTS REQUIRED:
Acetic Acid 0.2M: 1.5 ml of glacial acetic acid is made upto 100ml with distilled water.
Sodium Acetate Solution: 0.64 gm of sodium acetate or 2.72gm of sodium acetate trihydrate is dissolved in 100ml Distilled water.
PROCEDURE:
Pipette out exactly 36.2ml of sodium acetate solution into 100ml of standard flask and add 14.8ml of glacial acetic acid, make the volume 100ml using distilled water using distilled water. This gives 0.2 M of acetic acid and sodium acetate buffer. The pH is measured with pH meter.