When you prepare an aqueous acidic or basic solution and measure its pH, the result can be very different from what you might have expected based on calculations using the principles introduced in your general chemistry course. The explanation is that the pH meter is measuring the hydrogen ion activity and that chemical activities should be used in place of concentrations in the calculations.

In this module, you will review the equilibrium calculations associated with buffer solutions and apply the concept of chemical activities to these calculations.

Page author: David Miller
URL: http://www.csun.edu/~hcchm003/intro.html
Last updated: July 19, 1997