10 free IGCSE Chemistry Experimental Techniques & Analysis questions written in the style of Cambridge Chemistry papers: 5 multiple-choice and 5 structured, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers Experimental design, Chromatography, Separation & purification, Identification of ions & gases. Work through the questions below, then generate a full Experimental Techniques & Analysis paper with a fresh set every time.
Generate a full Experimental Techniques & Analysis paper →Two tests are done on an aqueous solution of salt X.
Test 1: aqueous sodium hydroxide is added and the mixture is warmed. Result: green precipitate, insoluble in excess.
Test 2: acidified aqueous silver nitrate added: white precipitate.
What is X?
Answer: C
Two dyes, M and N, are separated by paper chromatography using water as the solvent. The solvent front moves 9.0 cm from the baseline. M moves 4.0 cm and N moves 6.0 cm.
What is the Rf value of M and which dye is more soluble in water?
| Rf value of M | more soluble dye | |
|---|---|---|
| A | 2.25 | M |
| B | 0.44 | N |
| C | 2.25 | N |
| D | 0.44 | M |
Answer: B
A student needs to measure exactly 25.0 cm³ of an acid, add a varying volume of alkali from a scale, and collect the gas produced.
Which apparatus is used for each?
| 25.0 cm³ of acid | varying volume of alkali | collect gas | |
|---|---|---|---|
| A | measuring cylinder | burette | balance |
| B | volumetric pipette | measuring cylinder | beaker |
| C | volumetric pipette | burette | gas syringe |
| D | burette | volumetric pipette | gas syringe |
Answer: C
Which gas bleaches damp litmus paper?
Answer: A
Fig. shows a chromatogram of dyes A, B, C and D and mixture X. Which dyes are in X?
Answer: B
Two salts, A and B, are tested. The results are shown in Table 6.1.
| test | salt A | salt B |
|---|---|---|
| aqueous sodium hydroxide added, then in excess (warmed if no precipitate) | green precipitate, insoluble in excess | light blue precipitate, insoluble in excess |
| anion test | white precipitate with acidified aqueous barium nitrate | white precipitate with acidified aqueous silver nitrate |
Identify salt A and salt B. Give their formulae.
Aqueous ammonia is used instead of aqueous sodium hydroxide for the cation test on each salt. Describe what is seen for copper(II) ions with excess aqueous ammonia.
Explain why the anion tests with silver nitrate and barium nitrate are acidified with nitric acid.
Describe how a flame test would distinguish a lithium compound from a potassium compound.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | A: iron(II) sulfate, FeSO4; B: copper(II) chloride, CuCl2 A cation and anion: iron(II) sulfate B1 A formula FeSO4 B1 B cation and anion: copper(II) chloride B1 B formula CuCl2 B1 | 4 |
| (b) | light blue precipitate, soluble in excess, giving a dark blue solution correct precipitate B1 correct behaviour in excess with colour B1 | 2 |
| (c) | To remove carbonate ions, which would also give a white precipitate removes carbonate (and other) ions that would give a false positive B1 | 1 |
| (d) | Lithium gives a red flame; potassium gives a lilac flame lithium red B1 potassium lilac B1 | 2 |
This question is about choosing apparatus and methods.
Name the most suitable apparatus to measure each of: exactly 25.0 cm³ of a solution; a volume of gas; the time for a reaction.
A student measures 10 cm³ of acid with a 100 cm³ measuring cylinder. Explain why this is not accurate and suggest a better choice.
Describe how to measure the rate of the reaction between magnesium ribbon and hydrochloric acid by measuring gas volume.
Explain why the student should repeat each experiment.
A gas is collected over water. Suggest a gas for which this method is unsuitable, and explain.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | volumetric pipette; gas syringe; stopwatch (volumetric) pipette B1 gas syringe B1 stopwatch / timer B1 | 3 |
| (b) | large scale divisions, large percentage error; use 10 cm³ measuring cylinder / pipette / burette each division is large compared with 10 cm³ so the percentage error is large B1 use a 10 cm³ measuring cylinder / burette / pipette B1 | 2 |
| (c) | gas syringe connected to flask; add Mg, start timer; record volume at intervals; same mass/length of Mg and volume of acid connect a conical flask to a gas syringe with a bung and delivery tube B1 add the magnesium, replace the bung and start the timer B1 record the volume of gas at regular time intervals B1 control variables: same length of magnesium, same volume and concentration of acid, same temperature B1 | 4 |
| (d) | to check the results are repeatable / identify anomalies to identify anomalous results and calculate a mean (check repeatability) B1 | 1 |
| (e) | ammonia / hydrogen chloride; very soluble in water ammonia / hydrogen chloride / sulfur dioxide B1 it is very soluble in water B1 | 2 |
Rock salt is a mixture of sand and sodium chloride.
Describe how to obtain pure, dry salt crystals from rock salt.
Name the method used to separate ethanol from water.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | dissolve, filter, evaporate, crystallise add water and stir to dissolve the salt B1 filter to remove sand B1 heat the filtrate to evaporate some water B1 leave to crystallise and dry the crystals B1 | 4 |
| (b) | fractional distillation fractional distillation B1 | 1 |
Flame tests identify metal ions.
Describe how to carry out a flame test.
State the flame colours of sodium and copper(II) ions.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | clean wire loop in acid, dip in sample, into flame dip a clean nichrome wire loop (cleaned with acid) into the sample B1 hold it in a blue Bunsen flame B1 | 2 |
| (b) | yellow; blue-green sodium yellow B1 copper(II) blue-green B1 | 2 |
A mixture of two miscible liquids with different boiling points is separated.
Name the method.
Explain the role of the fractionating column.
State how the purity of the collected liquid can be checked.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | fractional distillation fractional distillation B1 | 1 |
| (b) | temperature gradient; repeated condensation it has a temperature gradient B1 vapours condense and re-evaporate, so the liquid with the lower boiling point reaches the top B1 | 2 |
| (c) | boiling point measure its boiling point (a pure liquid boils at a fixed temperature) B1 | 1 |
In the 0620 syllabus, Experimental Techniques & Analysis covers Experimental design, Chromatography, Separation & purification, Identification of ions & gases.
This page has 10 Experimental Techniques & Analysis questions with answers. For more, the free generator on mentorriyaz.in builds a new Experimental Techniques & Analysis paper with a full mark scheme each time you click.
Riyaz Shaikh has mentored IGCSE, IB and A Level students for 15+ years, one-on-one, online and in Mumbai. The hardest questions on this site are the ones he uses to find a student's weak points.
Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in