A 40.0 mL sample of a monoprotic weak acid solution of unknown concentration is…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A 40.0 mL sample of a monoprotic weak acid solution of unknown concentration is titrated with 0.100 M NaOH. The equivalence point is reached after 30.0 mL of the base have been delivered. At the point where 20.0 mL of NaOH have been added, the measured pH is 4.32.
Which of the following is closest to the acid’s Ka?
(a) 2.4×10−5
(b) 6.3×10−4
(c) 1.0×10−4
(d) 2.4×10−4