CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
During a titration experiment, a student investigates the reaction between a monoprotic weak base B and a standardized solution of 0.125 mol L⁻¹ HNO₃.
The student records that 18.60 mL of the acid titrant are required to reach the equivalence point for a 35.00 mL sample of the base.
(1) Describe, at the particulate level, what is meant by the term "equivalence point" for this titration.
(2) Determine the concentration (in mol L⁻¹) of the weak base B in the original sample, showing all calculations.
(3) Explain how the choice of indicator could lead to systematic error if its transition range does not encompass the pH at the equivalence point of this acid–base system.