Note:

CAIE IGCSE Chemistry Notes on Experimental techniques and Chemical analysis 2026/2027/2028 Exams

Syllabus Objectives:

12.1 Experimental design

Core

1 Name appropriate apparatus for the measurement of time, temperature, mass and volume, including:

(a) stop-watches

(b) thermometers

(c) balances

(d) burettes

(e) volumetric pipettes

(f) measuring cylinders

\(g) gas syringes

2 Suggest advantages and disadvantages of experimental methods and apparatus

3 Describe a:

(a) solvent as a substance that dissolves a solute

(b) solute as a substance that is dissolved in a solvent

(c) solution as a mixture of one or more solutes dissolved in a solvent

(d) saturated solution as a solution containing the maximum concentration of a solute dissolved in the solvent at a specified temperature

(e) residue as a substance that remains after evaporation, distillation, filtration or any similar process

(f) filtrate as a liquid or solution that has passed through a filter

Supplement

12.2 Acid–base titrations

Core 1 Describe an acid–base titration to include the use of a:

(a) burette (b) volumetric pipette (c) suitable indicator

2 Describe how to identify the end-point of a titration using an indicator 

12.3 Chromatography

Core

1 Describe how paper chromatography is used to separate mixtures of soluble coloured substances, using a suitable solvent

2 Interpret simple chromatograms to identify:

(a) unknown substances by comparison with known substances (b) pure and impure substances

Supplement

3 Describe how paper chromatography is used to separate mixtures of soluble colourless substances, using a suitable solvent and a locating agent Knowledge of specific locating agents is not required

4 State and use the equation for Rf : Rf = distance travelled by substance distance travelled by solvent

12.4 Separation and purification

Core

1 Describe and explain methods of separation and purification using:

(a) a suitable solvent

(b) filtration

(c) crystallisation

(d) simple distillation

(e) fractional distillation

2 Suggest suitable separation and purification techniques, given information about the substances involved

3 Identify substances and assess their purity using melting point and boiling point information

Supplement

12.5 Identification of ions and gases

Core

1 Describe tests to identify the anions:

(a) carbonate, CO3 2–, by reaction with dilute acid and then testing for carbon dioxide gas

(b) chloride, Cl – , bromide, Br – , and iodide, I – , by acidifying with dilute nitric acid then adding aqueous silver nitrate

(c) nitrate, NO3 – , reduction with aluminium foil and aqueous sodium hydroxide and then testing for ammonia gas

(d) sulfate, SO4 2–, by acidifying with dilute nitric acid and then adding aqueous barium nitrate

(e) sulfite, SO3 2–, by reaction with acidified aqueous potassium manganate(VII)

12.5 Identification of ions and gases continued

Core

2 Describe tests using aqueous sodium hydroxide and aqueous ammonia to identify the aqueous cations: (a) aluminium, Al 3+ (b) ammonium, NH4 + (c) calcium, Ca2+ (d) chromium(III), Cr3+ (e) copper(II), Cu2+ (f) iron(II), Fe2+ (g) iron(III), Fe3+ (h) zinc, Zn2+

3 Describe tests to identify the gases: (a) ammonia, NH3, using damp red litmus paper (b) carbon dioxide, CO2, using limewater (c) chlorine, Cl 2, using damp litmus paper (d) hydrogen, H2, using a lighted splint (e) oxygen, O2, using a glowing splint (f) sulfur dioxide, SO2, using acidified aqueous potassium manganate(VII)

4 Describe the use of a flame test to identify the cations: (a) lithium, Li+ (b) sodium, Na+ (c) potassium, K+ (d) calcium, Ca2+ (e) barium, Ba2+ (f) copper(II), Cu2+

Happy Learning,

Team,

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