AQA A-Level Chemistry –
Practicals test questions and
answers 2025-2026
1b. Outline how to carry out an acid-base titration. [10]
1. All apparatus rinsed with distilled water and then with the relevant
solution.
2. Using a pipette and pipette filler, pipette 25cm3 of NaOH into a conical
flask. Touch surface of solution with pipette tip to ensure correct quantity
is transferred.
3. Using a funnel, fill burette with acid and then remove funnel
4. Allow a small quantity of the acid to flow through the burette to
ensure jet space is filled. Note initial reading on burette.
- If jet space not filled, titre value higher than volume actually added.
5. Add 2-3 drops of phenolphthalein (or another suitable indicator) to the
conical flask and place it on a white tile - can see colour change better.
6. Add acid from burette into conical flask, swirling mixture during
addition, until indicator changes colour (pink → colourless).
7. During titration, rinse sides of conical flask with water → ensures all
acid is in solution.
8. Note the burette reading.
9. Repeat experiment but add acid dropwise towards the endpoint.
10. Continue repeating until at least two concordant results obtained
(within 0.10cm3).
Required Practical 1a
Make up a volumetric solution for titration [7]
1. Weigh the sample bottle containing the solid on a (2 dp) balance.
2. Transfer solid to beaker and reweigh sample bottle.
3. Record the difference in mass.
,4. Add distilled water and stir with a glass rod until all the solid has
dissolved.
5. Transfer to a volumetric flask with washings.
6. Make up to the 250cm3 mark with distilled water.
7. Invert flask.
Previous
Play
Next
Rewind 10 seconds
Move forward 10 seconds
Unmute
0:00
/
0:15
Full screen
Brainpower
Read More
What to make sure If using anhydrous sodium hydrogensulfate (NaHSO4)
Make sure it is not too old
- as it will have picked up water
- and mass values will not be as accurate.
Reducing uncertainties in measuring mass: [2+2]
→ Using a more accurate balance or a larger mass
→ reduce the uncertainty in weighing a solid.
→ Weighing by difference - weighing sample before and after addition and
then calculating difference -
→ ensure a more accurate measurement of the mass added.
Titration errors & improvements
1. How to read from burette
2. How to clean pipette
3. Why conical flask used instead of beaker and how to ensure it's clean?
Alk / acid?
4. How to ensure end-point is accurate [3]
, 5. Why should you only add a few drops of indicator?
6. Why do we use a white tile?
7. Why is a conical flask used?
8. Why is swirling necessary?
9. Why does rinsing the flask with water not affect the end point?
10. Why immediately remove funnel in titration?
1. bottom of meniscus - use white paper for clarity with dark liquids like
potassium manganate (K2MnO4)
2. Rinse the 25cm3 pipette with the soln of unknown conc.
3. It is easier to swirl the mixture in a conical flask without spilling the
contents.
→ The conical flask should be rinsed with deionised water.
→ Usually alkali
4. Add solⁿ slowly, swirl flask gently to mix the solⁿ.
→ Add soln dropwise near the end-point.
→ Use white tile under flask to see colour change.
5. Only a few drops required. If too much is added it will affect the
titration result.
6. To see indicator colour change better.
7. Can be swirled without losing any solution.
8. To ensure that solutions mix and so react completely.
9. Water does not react → doesn't affect number of moles present.
10. otherwise, some drops may fall through the titration after the initial
reading has been taken → lower titre vol recorded than used.
(Other 1) Outline how to carry out a mass change experiment.
What things would we use mass change experiments for?
How can we ensure that the (mass change) experiment has gone to
completion?
1. Crucible weighed on a balance and its mass is recorded (mass 1).
2. Some sample placed in the crucible.
3. Crucible and contents reweighed on a balance and its mass recorded
(mass 2).
Practicals test questions and
answers 2025-2026
1b. Outline how to carry out an acid-base titration. [10]
1. All apparatus rinsed with distilled water and then with the relevant
solution.
2. Using a pipette and pipette filler, pipette 25cm3 of NaOH into a conical
flask. Touch surface of solution with pipette tip to ensure correct quantity
is transferred.
3. Using a funnel, fill burette with acid and then remove funnel
4. Allow a small quantity of the acid to flow through the burette to
ensure jet space is filled. Note initial reading on burette.
- If jet space not filled, titre value higher than volume actually added.
5. Add 2-3 drops of phenolphthalein (or another suitable indicator) to the
conical flask and place it on a white tile - can see colour change better.
6. Add acid from burette into conical flask, swirling mixture during
addition, until indicator changes colour (pink → colourless).
7. During titration, rinse sides of conical flask with water → ensures all
acid is in solution.
8. Note the burette reading.
9. Repeat experiment but add acid dropwise towards the endpoint.
10. Continue repeating until at least two concordant results obtained
(within 0.10cm3).
Required Practical 1a
Make up a volumetric solution for titration [7]
1. Weigh the sample bottle containing the solid on a (2 dp) balance.
2. Transfer solid to beaker and reweigh sample bottle.
3. Record the difference in mass.
,4. Add distilled water and stir with a glass rod until all the solid has
dissolved.
5. Transfer to a volumetric flask with washings.
6. Make up to the 250cm3 mark with distilled water.
7. Invert flask.
Previous
Play
Next
Rewind 10 seconds
Move forward 10 seconds
Unmute
0:00
/
0:15
Full screen
Brainpower
Read More
What to make sure If using anhydrous sodium hydrogensulfate (NaHSO4)
Make sure it is not too old
- as it will have picked up water
- and mass values will not be as accurate.
Reducing uncertainties in measuring mass: [2+2]
→ Using a more accurate balance or a larger mass
→ reduce the uncertainty in weighing a solid.
→ Weighing by difference - weighing sample before and after addition and
then calculating difference -
→ ensure a more accurate measurement of the mass added.
Titration errors & improvements
1. How to read from burette
2. How to clean pipette
3. Why conical flask used instead of beaker and how to ensure it's clean?
Alk / acid?
4. How to ensure end-point is accurate [3]
, 5. Why should you only add a few drops of indicator?
6. Why do we use a white tile?
7. Why is a conical flask used?
8. Why is swirling necessary?
9. Why does rinsing the flask with water not affect the end point?
10. Why immediately remove funnel in titration?
1. bottom of meniscus - use white paper for clarity with dark liquids like
potassium manganate (K2MnO4)
2. Rinse the 25cm3 pipette with the soln of unknown conc.
3. It is easier to swirl the mixture in a conical flask without spilling the
contents.
→ The conical flask should be rinsed with deionised water.
→ Usually alkali
4. Add solⁿ slowly, swirl flask gently to mix the solⁿ.
→ Add soln dropwise near the end-point.
→ Use white tile under flask to see colour change.
5. Only a few drops required. If too much is added it will affect the
titration result.
6. To see indicator colour change better.
7. Can be swirled without losing any solution.
8. To ensure that solutions mix and so react completely.
9. Water does not react → doesn't affect number of moles present.
10. otherwise, some drops may fall through the titration after the initial
reading has been taken → lower titre vol recorded than used.
(Other 1) Outline how to carry out a mass change experiment.
What things would we use mass change experiments for?
How can we ensure that the (mass change) experiment has gone to
completion?
1. Crucible weighed on a balance and its mass is recorded (mass 1).
2. Some sample placed in the crucible.
3. Crucible and contents reweighed on a balance and its mass recorded
(mass 2).
