Choose measuring apparatus for the quantity and purpose
Match time, temperature, mass and liquid or gas volume to suitable apparatus, then explain the trade-off for a particular measurement.
Core and Extended · Chemistry 0620, 2026–2028. These paper-based method exercises support supervised laboratory learning; they do not certify practical competence.
Before you begin
- Read a labelled scale and attach a unit to a measurement.
- Distinguish measuring a quantity from changing a variable.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which pairing measures mass?
What you will learn
- Name the required apparatus for time, temperature, mass and volume.
- Compare measuring devices using the quantity, range, resolution and purpose supplied.
Begin with the quantity you need
Use a stop-watch for elapsed time, a thermometer for temperature and a balance for mass. For volume, distinguish liquids from gases: a measuring cylinder gives a range of approximate liquid volumes; a volumetric pipette delivers one specified liquid volume accurately when used correctly; a burette delivers a variable liquid volume measured from two readings. A gas syringe measures collected gas volume directly when a suitable reaction setup is gas-tight.
A beaker's rough markings do not make it interchangeable with a volumetric pipette for a precise aliquot. A 25.0 cm³ volumetric pipette is designed for that fixed volume, rather than any arbitrarily chosen 12.0 cm³ volume. A burette is useful when the delivered amount must change, as in titration. The apparatus name alone does not give its exact uncertainty: use the instrument markings or uncertainty supplied in the problem.
Explain the limitation as well as the advantage
Select a range large enough for the expected measurement and a readable scale fine enough for the task. In a paper scenario, a balance displaying 0.01 g provides finer resolution than one displaying 0.1 g, but resolution is not a guarantee of accuracy. Zero error, calibration and correct use still matter. A stop-watch can display small intervals while human starting and stopping introduces reaction-time variation.
A gas syringe avoids assuming all gas is insoluble in water, but leaks, sticking and insufficient capacity can affect collection. Collection over water can be unsuitable when the gas dissolves appreciably or reacts with water. Neither method is universally superior: explain the choice from the supplied gas properties and apparatus limitations. Real work requires an appropriate supervised method and the laboratory's risk assessment.
Pause and explain
Which apparatus suits a varying liquid volume delivered to an endpoint?
Worked example
For a hypothetical investigation, measure 25.0 cm³ of solution accurately, the volume of gas formed up to 60 cm³, and the time taken. Choose apparatus and one limitation for each.
Show the worked solution
- A 25.0 cm³ volumetric pipette suits the fixed liquid aliquot; it does not deliver arbitrary volumes.
- A gas syringe with sufficient capacity measures gas volume, provided the apparatus is gas-tight and the plunger moves freely.
- A stop-watch measures elapsed time, but human reaction time can affect the recorded interval.
Answer 25.0 cm³ volumetric pipette; suitably sized gas syringe; stop-watch. Explain fixed-volume, leakage/sticking and reaction-time limitations respectively.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Match time, temperature, mass and gas volume to the required apparatus and units.
Give me a hint
Decide what the scale measures before choosing the unit.
Compare my reasoning
- Use a stop-watch for time in s and a thermometer for temperature in °C.
- Use a balance for mass in g.
- Use a suitable gas syringe for gas volume in cm³, with enough capacity and a gas-tight setup.
Stop-watch/s; thermometer/°C; balance/g; gas syringe/cm³.
Look for these in your work
- Every apparatus matches its quantity.
- Appropriate units and the gas-collection limitation are included.
Choose between a measuring cylinder, 25.0 cm³ volumetric pipette and burette for an approximate 40 cm³ portion, an accurate fixed 25.0 cm³ aliquot and a titration delivery. Justify each.
Give me a hint
Compare approximate, fixed and adjustable purposes.
Compare my reasoning
- A suitable measuring cylinder serves the approximate 40 cm³ portion.
- The 25.0 cm³ volumetric pipette serves that accurate fixed aliquot.
- The burette serves variable delivery to a titration endpoint, measured by two readings.
Measuring cylinder; 25.0 cm³ volumetric pipette; burette, justified by approximate, fixed and variable delivery respectively.
Look for these in your work
- The stated purpose controls the choice.
- No fixed pipette is treated as an arbitrary-volume device.
Two hypothetical balances have display increments of 0.1 g and 0.01 g. A 1.25 g target needs finer mass resolution, but the second balance shows 0.08 g when empty. Evaluate the choice.
Give me a hint
Separate resolution from a possible zero offset.
Compare my reasoning
- The 0.01 g display has finer resolution for the target.
- Its empty reading suggests a zero offset that must be investigated or corrected by an appropriate zeroing procedure.
- Finer resolution alone does not establish accuracy, and repeated readings do not automatically remove a systematic offset.
Prefer the finer-resolution balance only after addressing the observed zero offset; a fine display alone does not guarantee accurate mass.
Look for these in your work
- Resolution and accuracy are distinguished.
- The observed offset leads to a specific improvement rather than a generic repeat.
Common mistakes
- Using the same volume device for every liquid and gas task.
- Calling fine resolution proof of a perfectly accurate result.
- Ignoring an instrument's capacity or fixed-volume purpose.
- Giving a general claim that every gas can be collected over water.
What can you explain now?
Which device delivers one specified accurate liquid volume?
Compare with the explanation
A volumetric pipette of the required capacity.
Its fixed-volume purpose differs from a burette's adjustable delivered amount.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Recall all seven named apparatus types and explain a use and a limitation for each volume device.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.