These materials are the intellectual property of Lotus Mohammad and are for personal use only. Any reproduction,
distribution, or sharing without explicit written permission is strictly prohibited.
OCR A A Level Chemistry Practicals
PAG 1 – Moles Determination
● Weigh a sample of magnesium ribbon.
→ Ensures accurate mass measurement for mole calculation.
om
● React with excess hydrochloric acid.
→ Ensures that all magnesium reacts, so the amount of hydrogen gas is accurately
measured.
l.c
● Collect and measure the volume of hydrogen gas produced.
→ Allows for the calculation of the moles of gas produced based on the ideal gas
ai
equation.
● Use the ideal gas equation to calculate the number of moles of hydrogen.
gm
→ Relates the volume of gas produced to the number of moles using standard
temperature and pressure conditions. PV=nRT
● Calculate the relative atomic mass of magnesium.
@
→ Allows for determination of magnesium’s molar mass by relating moles of hydrogen
to magnesium.
72
PAG 2 – Acid-Base Titration
ct
● Prepare a standard solution of sodium carbonate.
→ Provides a solution of known concentration for titration.
so
● Pipette a measured volume into a conical flask.
tu
→ Ensures a precise volume of sodium carbonate is used for the titration.
● Add a few drops of phenolphthalein indicator.
lo
→ Provides a visible endpoint for the titration (colour change from pink to colourless).
● Titrate with hydrochloric acid from a burette.
→ Allows for the gradual addition of acid to neutralize the base and reach the endpoint.
● Record the volume of acid used at the endpoint.
→ Provides the data needed to calculate the concentration of hydrochloric acid.
,
These materials are the intellectual property of Lotus Mohammad and are for personal use only. Any reproduction,
distribution, or sharing without explicit written permission is strictly prohibited.
● Calculate the concentration of the acid.
→ Determines the unknown concentration of the acid by using the titration formula.
PAG 3 – Enthalpy Determination
om
● Weigh a known mass of solid fuel.
→ Ensures an accurate mass of fuel is used to calculate the energy released.
l.c
● Burn the fuel under a calorimeter containing water.
→ Allows heat from the combustion to be transferred to the water, raising its
temperature.
ai
● Measure the temperature change of the water.
→ Quantifies the heat absorbed by the water, which is used to calculate the energy
gm
released by the fuel.
● Calculate the enthalpy change of combustion.
→ Determines the energy released per mole of fuel, based on the temperature change
@
of the water.
72
PAG 4 – Qualitative Analysis of Ions
ct
● Add dilute hydrochloric acid to the sample.
→ Removes carbonate ions (CO₃²⁻) by releasing carbon dioxide gas.
so
● Add barium chloride solution.
→ Forms a white precipitate of barium sulfate (BaSO₄) if sulfate ions (SO₄²⁻) are
tu
present.
● Add silver nitrate solution.
lo
→ Forms a white precipitate of silver chloride (AgCl) if chloride ions (Cl⁻) are present.
● Add ammonia solution to the precipitate.
→ Differentiates between halide ions by observing whether the precipitate dissolves (for
chloride, bromide, and iodide).
PAG 5 – Synthesis of an Organic Liquid
distribution, or sharing without explicit written permission is strictly prohibited.
OCR A A Level Chemistry Practicals
PAG 1 – Moles Determination
● Weigh a sample of magnesium ribbon.
→ Ensures accurate mass measurement for mole calculation.
om
● React with excess hydrochloric acid.
→ Ensures that all magnesium reacts, so the amount of hydrogen gas is accurately
measured.
l.c
● Collect and measure the volume of hydrogen gas produced.
→ Allows for the calculation of the moles of gas produced based on the ideal gas
ai
equation.
● Use the ideal gas equation to calculate the number of moles of hydrogen.
gm
→ Relates the volume of gas produced to the number of moles using standard
temperature and pressure conditions. PV=nRT
● Calculate the relative atomic mass of magnesium.
@
→ Allows for determination of magnesium’s molar mass by relating moles of hydrogen
to magnesium.
72
PAG 2 – Acid-Base Titration
ct
● Prepare a standard solution of sodium carbonate.
→ Provides a solution of known concentration for titration.
so
● Pipette a measured volume into a conical flask.
tu
→ Ensures a precise volume of sodium carbonate is used for the titration.
● Add a few drops of phenolphthalein indicator.
lo
→ Provides a visible endpoint for the titration (colour change from pink to colourless).
● Titrate with hydrochloric acid from a burette.
→ Allows for the gradual addition of acid to neutralize the base and reach the endpoint.
● Record the volume of acid used at the endpoint.
→ Provides the data needed to calculate the concentration of hydrochloric acid.
,
These materials are the intellectual property of Lotus Mohammad and are for personal use only. Any reproduction,
distribution, or sharing without explicit written permission is strictly prohibited.
● Calculate the concentration of the acid.
→ Determines the unknown concentration of the acid by using the titration formula.
PAG 3 – Enthalpy Determination
om
● Weigh a known mass of solid fuel.
→ Ensures an accurate mass of fuel is used to calculate the energy released.
l.c
● Burn the fuel under a calorimeter containing water.
→ Allows heat from the combustion to be transferred to the water, raising its
temperature.
ai
● Measure the temperature change of the water.
→ Quantifies the heat absorbed by the water, which is used to calculate the energy
gm
released by the fuel.
● Calculate the enthalpy change of combustion.
→ Determines the energy released per mole of fuel, based on the temperature change
@
of the water.
72
PAG 4 – Qualitative Analysis of Ions
ct
● Add dilute hydrochloric acid to the sample.
→ Removes carbonate ions (CO₃²⁻) by releasing carbon dioxide gas.
so
● Add barium chloride solution.
→ Forms a white precipitate of barium sulfate (BaSO₄) if sulfate ions (SO₄²⁻) are
tu
present.
● Add silver nitrate solution.
lo
→ Forms a white precipitate of silver chloride (AgCl) if chloride ions (Cl⁻) are present.
● Add ammonia solution to the precipitate.
→ Differentiates between halide ions by observing whether the precipitate dissolves (for
chloride, bromide, and iodide).
PAG 5 – Synthesis of an Organic Liquid
