A buffer solution is 0.50 M in triethylamine ( ) and 0.50 M in triethylammonium…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A buffer solution is 0.50 M in triethylamine (N(CH2CH3)3) and 0.50 M in triethylammonium chloride at 25 °C. The solution is then diluted ten-fold with distilled water at the same temperature. Which statement best describes the resulting change in pH?
(a) The pH decreases by about 1 unit because both buffer components are less able to neutralize added H+ or OH− after dilution.
(b) The pH changes negligibly because the ratio of base to conjugate acid remains essentially constant.
(c) The pH moves toward neutrality, becoming approximately 7.0, because dilution leaves mostly water.
(d) The pH increases by about 1 unit because the weaker conjugate acid ionizes less after dilution.