The ability of a solution to resist changes to the pH from

Last updated: 5/9/2023

The ability of a solution to resist changes to the pH from added acid or base depends upon the amount of weak acid and weak base The buffering capacity is the ratio of weak acid to weak base and the best buffering occurs when these are equal making the buffering capacity equal to 1 In the above buffer the buffering capacity is the ratio of H PO4 1 to HPO4 or K H PO4 H 0 K 4 44 x 105 K 8 HPO42 5 55 x 10 5 10 Here the buffering capacity is close to 1 0 8 and so the buffering capacity is When the buffering capacity is 1 the H 0 K and the pH pKa This helps chemists choose the right buffer for the needed pH To buffer at pH 7 the weak acid should a pK of close to 7 True or False the weak acid should have K of close to 1 x 107 True or False A good B bad C true D false W