pH Determination of Acetic Acid-Sodium Acetate Buffer: An Application of Henderson-Hasselbalch Equation at Room Temperature

In article, we have reported the applying of Henderson-Hasselbalch equation in determination of pH of acetic acid and sodium acetate buffer solutions at about 298 Kelvin as room temperature. In preparation of these buffer solutions, we have taken 1.5 ml of glacial acetic acid into 100 ml of standard flask for making up 0.2M of acetic acid solution, and 0.64 gm of sodium acetate were dissolved into 100 ml distilled water. Now, we taken 36.2 ml prepared solution of sodium acetate into 100 ml of standard flask and added 14.8 ml of prepared acetic acid to make its volume 100 ml by using of distilled water, it is a buffer. In measuring of pH of prepared buffer solutions, we have been using a calibrated digital pen pH meter for accurate and quick reading. In observation, the pH of buffer solutions a quite fluctuation was appeared. But, it has gradually raised by adding small amount of basic 5N NaOH solution into buffer sample, and, an adjusted pH was being to 4.7 as well.