Buffer Video Lessons

Concept:

# Problem: The capacity of a buffer is greatest when which of the following is true?A. [weak acid] &gt; [its conjugate base]B. [weak acid] = [its conjugate base]C. [weak acid] &lt; [its conjugate base]D. buffer capacity does not depend on the relative concentrations of the weak acid and its conjugate baseE. pH = 7

###### FREE Expert Solution

We’re being asked to determine which of the statements about buffer capacity is true

Recall that a buffer can be composed of the following:

weak base and its conjugate acid
weak acid and its conjugate base
weak acid and a strong base

▪ concentration of weak acid > concentration of strong base

weak base and a strong acid

concentration of weak base > concentration of strong acid

The maximum buffering capacity of a solution is when the pH of the solution is equal to pKa and the buffer range of a solution is pH = pKa ± 1.

maximum buffering capacity:              pH = pKa

buffering range:              pH = pKa ± 1

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###### Problem Details

The capacity of a buffer is greatest when which of the following is true?

A. [weak acid] > [its conjugate base]

B. [weak acid] = [its conjugate base]

C. [weak acid] < [its conjugate base]

D. buffer capacity does not depend on the relative concentrations of the weak acid and its conjugate base

E. pH = 7