Chemical Analysis | AQA GCSE Chemistry, Foundation tier (8462)
Chemical Analysis
- 100 questions
- 8 subtopics
- Paper 2
- Paper 2
Chemical Analysis is examined in Chemistry Paper 2.
It covers pure substances, formulations, chromatography, tests for hydrogen, oxygen, carbon dioxide and chlorine, flame tests, metal hydroxides, tests for carbonates, halides and sulfates and flame emission spectroscopy.
Sample questions from Chemical Analysis
Answer each one closed book first, then open the answer.
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Pure substances
What is the difference between the way a pure compound changes state and the way a mixture does?
Show the answer
A pure compound melts and boils at specific fixed temperatures, while a mixture melts and boils over a range of temperatures. -
Formulations
Name three household products that are formulations.
Show the answer
Paints, medicines and cleaning agents are all formulations. -
Chromatography
A spot moves 3.6 cm from the origin while the solvent moves 8.0 cm. Calculate its Rf value.
Show the answer
Rf is 3.6 ÷ 8.0, which is 0.45. -
Tests for hydrogen, oxygen, carbon dioxide and chlorine
A glowing splint bursts back into flame when it is pushed into a test tube of gas. Which gas is present?
Show the answer
It is oxygen. -
Flame tests
What flame colour do sodium compounds produce?
Show the answer
Sodium compounds produce a yellow flame. -
Metal hydroxides
A solution gives a white precipitate with sodium hydroxide solution and the precipitate remains when more is added. Which ions could be present?
Show the answer
Calcium ions or magnesium ions. -
Tests for carbonates, halides and sulfates
What precipitate does a solution containing chloride ions give with silver nitrate?
Show the answer
A white precipitate of silver chloride. -
Flame emission spectroscopy
Describe how a solution is analysed by flame emission spectroscopy.
Show the answer
The sample is put into a flame and the light given out is passed through a spectroscope.
The 8 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Pure substances | The chemical meaning of a pure substance, why pure substances melt and boil at fixed temperatures while mixtures change state over a range, using melting and boiling points to test purity, and the everyday meaning of pure compared with the chemist's. | 12 |
| Formulations | What a formulation is and why its components are measured in controlled quantities, the purpose of each ingredient, examples such as paints, medicines, cleaning agents, fertilisers, fuels, alloys and food sauces, and telling a formulation from a single compound or a natural mixture. | 11 |
| Chromatography | The stationary and mobile phases, what decides how far a substance travels, how Rf values are defined and calculated, reading purity from a chromatogram, and why the start line is pencil and the solvent starts below it. | 16 |
| Tests for hydrogen, oxygen, carbon dioxide and chlorine | The burning splint test for hydrogen, the glowing splint test for oxygen, limewater turning milky for carbon dioxide, damp litmus paper bleached white by chlorine, why each test is carried out as it is, and identifying a gas from the result. | 12 |
| Flame tests | Which metal ions a flame test identifies, how it is carried out, the crimson, yellow, lilac, orange-red and green flames of lithium, sodium, potassium, calcium and copper, and why one colour can mask another. | 13 |
| Metal hydroxides | Precipitating metal hydroxides with sodium hydroxide solution, the white precipitates of aluminium, calcium and magnesium and how excess tells them apart, the coloured precipitates of copper(II), iron(II) and iron(III), and their equations. | 12 |
| Tests for carbonates, halides and sulfates | Testing for carbonates with dilute acid and limewater, for halide ions with silver nitrate and dilute nitric acid giving white, cream and yellow precipitates, and for sulfate ions with barium chloride and dilute hydrochloric acid, identifying a compound from two sets of tests, and the advantages of instrumental methods. | 14 |
| Flame emission spectroscopy | Flame emission spectroscopy as an instrumental method for metal ions in solution, why it is chosen over a flame test, how the spectroscope produces a line spectrum, and using reference spectra to identify metal ions and compare their concentrations. | 10 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
AQA GCSE Chemistry, Foundation tier Active Recall Guide
Every topic, not just this one. 1,386 questions with their answers.