Effect of Concetration and Temperature on the Ka of Acetic Acid

The purpose of this experiment was to determine whether or not the temperature and the concentration of an acid would have an effect on the dissociation constant, Ka, of acetic acid. To determine this, quantities of a stock solution of 2.0M acetic acid and distilled water were heated or cooled to temperatures of 5, 25, or 45 degrees Celsius, and then the two were mixed to form a new concentration of 0.5M, 1.0M, or 1.5M. With the temperature and the concentration of the new solution at known values, the pH was measured and recorded. Using the pH of the solution, the concentrations of the various parts of the solution and the Ka were calculated. With the values of Ka, a two factor DOE test was run on the data from the trials to determine if either factor had an effect on the Ka. The conclusion was drawn that the temperature does have an effect on the Ka. When the temperature of the acid is increased, so does the Ka. The concentration, however, had no significant effect and it was concluded that the concentration of the acid does not affect the Ka of that acid

Research Done By:

Kyle Diem
L'Anse Creuse High School North

Rachel LaCasse
Center Line High School

Mike Van Andel
L'Anser Creuse High School