A buffer is prepared by mixing equimolar solutions of acetic acid and sodium acetate…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A buffer is prepared by mixing equimolar solutions of acetic acid and sodium acetate to the same total concentration as a second buffer in which the acetate ion concentration is doubled while the acetic-acid concentration is also doubled. Which statement describes the most significant difference between the two buffers?
(a) The second buffer has a higher initial pH because the larger acetate concentration shifts the equilibrium toward the base form.
(b) Both buffers possess the same capacity to absorb added acid or base because buffer capacity depends solely on the ratio [A−]/[HA].
(c) The second buffer has a larger capacity to neutralize added strong acid or base because both components are present at higher concentrations.
(d) The first buffer resists pH change more effectively toward added strong base because it contains relatively more acetic acid.