Choose1 markBoth boards
Which instrument is most suitable for measuring 25.0 cm³ of dilute acid to the nearest 0.1 cm³?
Show the mark scheme and the examiner note
Answer: Burette
- Precision needed: 0.1 cm³
- Burette reads to 0.05 cm³, so it meets the precision requirement
- A. Burette — Correct: a burette reads to 0.05 cm³, which is fine enough for the nearest 0.1 cm³.
- B. Measuring cylinder — A 50 cm³ measuring cylinder is usually graduated in 1 cm³ steps, so it cannot read to 0.1 cm³.
- C. Beaker — A beaker has approximate markings only. It is for holding, not measuring.
- D. Pipette — Accurate, but a pipette delivers one fixed volume. It cannot measure an arbitrary 25.0 cm³ chosen by you.
Examiner technique: Instrument questions are answered in two steps: what precision is demanded, then which instrument provides at least that precision.