Final answer:
The most effective buffers have equal concentrations of an acid and its conjugate base, allowing them to effectively neutralize both added base and acid. Buffers with unequal ratios of acid and conjugate base have lower buffer capacity. Higher amounts of weak acid and conjugate base result in higher buffer capacity.
Step-by-step explanation:
The most effective buffers contain equal concentrations of an acid and its conjugate base. A buffer that contains approximately equal amounts of a weak acid and its conjugate base in solution is equally effective at neutralizing either added base or added acid. This is shown in Figure 15.5.2 for an acetic acid/sodium acetate buffer. Adding a given amount of strong acid shifts the system along the horizontal axis to the left, whereas adding the same amount of strong base shifts the system the same distance to the right. In either case, the change in the ratio of CH3CO₂ to CH³CO₂H from 1:1 reduces the buffer capacity of the solution.
The most effective buffers contain equal concentrations of an acid and its conjugate base. A buffer that contains approximately equal amounts of a weak acid and its conjugate base in solution is equally effective at neutralizing either added base or added acid. This is shown in Figure 18.2.2 for an acetic acid/sodium acetate buffer. Adding a given amount of strong acid shifts the system along the horizontal axis to the left, whereas adding the same amount of strong base shifts the system the same distance to the right. In either case, the change in the ratio of CH3CO₂ to CH³CO₂H from 1:1 reduces the buffer capacity of the solution.
Higher the amount of weak acid/conjugate base higher the buffer capacity. The buffer has an equal amount of weak acid and its conjugate base has a higher buffer capacity than the same buffer that has an unequal ratio of the acid and its conjugate base.