EDEXCEL A LEVEL CHEMISTRY PAPER 2
2026 ADVANCED REVIEW SCRIPT WITH
VERIFIED SOLUTIONS
◉Core Practical 2: prepare a standard solution from a solid acid and
use it find the concentration of a solution of sodium hydroxide.
Answer: METHOD:
Weigh an empty test tube. Scoop approximately 2.5 g of sulfamic
acid into the test tube.Reweigh the test tube and its contents
accurately.Dissolve the sulfamic acid in approximately 100 cm3 of
water in a beaker.Transfer the solution, including the washings, into
a 250 cm3 volumetric flask and make the solution up to the mark
with deionised water.Prepare your apparatus for the titration. The
burette will contain the acid and the conical flask will contain the
sodium hydroxide solution.Pour a 25.0 cm3 aliquot of sodium
hydroxide solution of unknown concentration into the 250 cm3
conical flask.Add four drops of methyl orange indicator to the
conical flask.Titrate the contents of the flask against the sulfamic
acid solution you prepared. Burette readings should be to the
nearest 0.05cm3. Continue to conduct titrations until you have two
concordant titres.
ERRORS:
, Transfer loss, important to wash glass rod, beaker, funnel with
deionised water and transfer washings. Weigh solid by difference,
and careful not too loose solid when transferring to the beaker. Acid
must have a high molar mass to reduce weighing errors, and sample
must be pure.
◉Core Practical 3: find the concentration of a solution of
hydrochloric acid Answer: METHOD:
Wash out the 250 cm3 volumetric flask with distilled water.Use the
pipette to transfer 25.0 cm3 of the hydrochloric acid solution into
the volumetric flask. Make the solution up to the mark with
deionised water.Prepare your apparatus for the titration. The
burette should contain the sodium hydroxide solution and the
conical flask should contain the dilute hydrochloric acid
solution.Pour a 25.0 cm3 aliquot of the diluted hydrochloric acid
into the conical flask. Add two drops of phenolphthalein
indicator.Titrate the contents of the flask against the sodium
hydroxide solution (previously standardised). All burette readings
should be recorded to the nearest 0.05 cm3.The end point of this
titration is indicated by the contents of the flask becoming pale pink.
Continued swirling will cause the pink colour to fade and disappear -
if the pink colour persists for 5 seconds or more, then the end point
has been reached.Continue to conduct titrations until you have two
concordant titres (within 0.2 of each other).
ERRORS:
2026 ADVANCED REVIEW SCRIPT WITH
VERIFIED SOLUTIONS
◉Core Practical 2: prepare a standard solution from a solid acid and
use it find the concentration of a solution of sodium hydroxide.
Answer: METHOD:
Weigh an empty test tube. Scoop approximately 2.5 g of sulfamic
acid into the test tube.Reweigh the test tube and its contents
accurately.Dissolve the sulfamic acid in approximately 100 cm3 of
water in a beaker.Transfer the solution, including the washings, into
a 250 cm3 volumetric flask and make the solution up to the mark
with deionised water.Prepare your apparatus for the titration. The
burette will contain the acid and the conical flask will contain the
sodium hydroxide solution.Pour a 25.0 cm3 aliquot of sodium
hydroxide solution of unknown concentration into the 250 cm3
conical flask.Add four drops of methyl orange indicator to the
conical flask.Titrate the contents of the flask against the sulfamic
acid solution you prepared. Burette readings should be to the
nearest 0.05cm3. Continue to conduct titrations until you have two
concordant titres.
ERRORS:
, Transfer loss, important to wash glass rod, beaker, funnel with
deionised water and transfer washings. Weigh solid by difference,
and careful not too loose solid when transferring to the beaker. Acid
must have a high molar mass to reduce weighing errors, and sample
must be pure.
◉Core Practical 3: find the concentration of a solution of
hydrochloric acid Answer: METHOD:
Wash out the 250 cm3 volumetric flask with distilled water.Use the
pipette to transfer 25.0 cm3 of the hydrochloric acid solution into
the volumetric flask. Make the solution up to the mark with
deionised water.Prepare your apparatus for the titration. The
burette should contain the sodium hydroxide solution and the
conical flask should contain the dilute hydrochloric acid
solution.Pour a 25.0 cm3 aliquot of the diluted hydrochloric acid
into the conical flask. Add two drops of phenolphthalein
indicator.Titrate the contents of the flask against the sodium
hydroxide solution (previously standardised). All burette readings
should be recorded to the nearest 0.05 cm3.The end point of this
titration is indicated by the contents of the flask becoming pale pink.
Continued swirling will cause the pink colour to fade and disappear -
if the pink colour persists for 5 seconds or more, then the end point
has been reached.Continue to conduct titrations until you have two
concordant titres (within 0.2 of each other).
ERRORS:
