Question

can you help me define a buffer and explain how a buffer

Answer 1

A buffer is a combination of a weak acid and the salt of its salt (acetic acid and sodium acetate) or a weak base and its salt (NH3 and NH4Cl). Buffers resist a change in pH. Here is how an acid buffer works. Say it is HAc and Ac^-.

If a strong acid, such as HCl is added, the Ac^- reacts with it to form HAc, the weak acid so the addition of the strong acid is mitigated. If a strong base is added, such as NaOH, then the HAc reacts with it to form Ac^- and H2O and the pH change is resisted.