Utility of pH meter in the study of adsorption of Acetic acid on activated Charcoal

Abstract

Absorption of acetic acid on activated charcoal has been studied using pH meter in the concentration range 0.1 to 0.02 normal acetic acid solutions at 28oC. A weighed amount of activated charcoal was added to 50ml of acetic acid solution. Adsorption of acetic acid decreases the concentration of H+ ions in the solution. The pH of the solution consequently increases. The pH of the solution was measured using pH meter before and after adsorption. The normality of acetic acid solution after adsorption was determined from the standard plot of degree of dissociation of acetic acid versus pH of the solution. The amount of acetic acid adsorbed per gram of activated charcoal was calculated and the data was used to plot Freundlich and Langmuir adsorption isotherms. The constants in Freundlich adsorption isotherm were determined and reported here. The specific surface area of activated charcoal was calculated from the Langmuir adsorption isotherm. The aim of this study is to show the utility of pH meter in the adsorption studies of weak acid on activated charcoal.