Titration Curves: Flashcards
Revise equivalence points, half-equivalence, curve shapes and indicators.
Titration Curves: Flashcards
- QuestionWhat is a titration curve?Answer
A graph of the pH of the mixture against the volume of titrant added.
- QuestionWhat is the equivalence point?Answer
The point where just enough titrant has been added to react completely with the analyte, according to the balanced equation.
- QuestionWhat is the pH at the equivalence point of a strong acid–strong base titration?Answer
7.00 (at 25 °C), because the salt formed is neutral.
- QuestionIs the equivalence point of a weak acid–strong base titration above or below 7?Answer
Above 7, because the conjugate base of the weak acid is weakly basic.
- QuestionWhat is the pH at the half-equivalence point of a weak acid titration?Answer
pH = pKa, because [HA] = [A⁻] there.
- QuestionWhat is the end point?Answer
The point where the indicator changes colour. Ideally it matches the equivalence point.
- QuestionWhich indicator suits a weak acid–strong base titration?Answer
Phenolphthalein (changes around pH 8.2–10.0), within the steep jump.
- QuestionIs the equivalence point of a strong acid–weak base titration above or below 7?Answer
Below 7, because the conjugate acid of the weak base is weakly acidic.
- QuestionWhy are titrations so precise near the equivalence point?Answer
The pH changes very steeply there, so a single drop causes a large, easily seen change.
Tip: press Space to flip and ← → to move between cards.