Two separate titrations are carried out at 25 °C using 25.0 mL samples of acetic acid ( )
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Two separate titrations are carried out at 25 °C using 25.0 mL samples of acetic acid (Ka=1.8×10−5).
• Experiment 1: 0.10M acetic acid is titrated with 0.10M NaOH.
• Experiment 2: 0.20M acetic acid is titrated with the same 0.10M NaOH.
Which statement correctly compares the shapes of the two resulting titration curves?
(a) Both titrations reach the same pH at the equivalence point because this pH depends only on Ka of acetic acid.
(b) Experiment 1 shows a larger change in pH per millilitre of base added near the equivalence point because its initial acid is more dilute.
(c) Experiment 2 exhibits a steeper rise in pH near the equivalence point and a slightly higher pH at the equivalence point than Experiment 1.
(d) The two titrations have identical equivalence volumes because the NaOH concentration is the same in both titrations.