CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A monoprotic weak acid, HA, with Ka=1.0×10−4 is titrated at 25 °C. Exactly 50.0 mL of 0.100 M HA is placed in a beaker and titrated with 0.100 M NaOH.
Answer the following questions.
(a) Calculate the volume of NaOH required to reach the equivalence point.
(b) Determine the pH of the solution at the equivalence point.
(c) Three common indicators are available: bromocresol green (pH 3.8–5.4), litmus (pH 5.0–8.0), and phenolphthalein (pH 8.2–10.0). Identify the indicator most suitable for this titration and justify your choice.
(d) On axes of pH versus volume of NaOH added, sketch a qualitative titration curve for this experiment. Label (i) the buffer region, (ii) the equivalence point volume, and (iii) the approximate pH at the equivalence point.