How to calculate the pH of a buffer solution?

To calculate the pH of a buffer solution, you can use the Henderson-Hasselbalch equation, which is pH pKa log(A-/HA). Here, pKa is the negative logarithm of the acid dissociation constant, A- is the concentration of the conjugate base, and HA is the concentration of the weak acid. By plugging in these values, you can determine the pH of the buffer solution.