How Do You Calculate A Buffer Solution?
A buffer is a solution containing a mixture of a weak acid and its conjugate base. Unlike the pH of pure water, the pH of a buffered solution only changes slowly as more acid or base is added, so buffers help maintain a stable pH. This is especially important for biochemistry experiments, where changes in pH can affect the rate at which a reaction occurs. If you need to calculate how much weak acid and base to add to make a buffer, follow these steps. Determine what acid-base pair you intend to use for your buffer solution, and then find the weak acid you want to use from the list in the Resources section. Copy down the pKa value for the acid. In general, it’s best to choose an acid with a pKa close to the pH where you want to buffer the solution. Use the equation for buffer pH to determine what ratio of weak acid to conjugate base you need. The equation is pH = pKa + log ([conjugate base concentration] / [weak acid concentration]). Since you know the desired pH and the pKa, you can pl
