Two students titrate separate 25.0 mL samples of a monoprotic strong acid with 0.120…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Two students titrate separate 25.0 mL samples of a monoprotic strong acid with 0.120 M NaOH.
• Student A stops the titration when a very faint pink color first appears; the measured pH at that point is 6.0.
• Student B continues adding titrant until a deep pink color persists; the measured pH at that point is 9.5.
Which prediction about the molarity each student reports for the acid is most accurate?
(a) Both students will report concentrations that are overestimated, with Student A’s error being larger.
(b) Student A will report a concentration that is overestimated, whereas Student B will report a concentration that is underestimated.
(c) Student A will report a concentration that is underestimated, whereas Student B will report a concentration that is overestimated.
(d) Student A will report a concentration that is underestimated, whereas Student B will report a concentration that is approximately correct.