Buffer weak base - conjugate acid
The buffer consisting of a weak base and its conjugate acid is prepared by mixing relatively large amounts of a weak base and a salt thereof. For example, you can get a tampon of this type by mixing a solution of ammonia (NH 3) with an ammonium chloride (NH 4 Cl).
The reasoning that we practice is identical to the previous one. Based on the equilibrium of the ammonia hydrolysis in H 2 O, containing both the kind that the NH 3 NH 4 +
It is obtained by an expression very similar to the previous one that allow to go back to the pH of this solution:
That is the equation of Henderson-Hasselbach for tampons constituted by a weak base and a salt of its conjugate acid.
Even in this case are subject to the consideration previously. The buffer to be effective it must be made of relatively large amounts of weak base and conjugate acid (salt).