Hydrocarbons | AQA A-Level Chemistry (7405)
Hydrocarbons
- 118 questions
- 7 subtopics
- Organic chemistry, examined on Paper 2
- Paper 2 and Paper 3
Hydrocarbons is examined on Papers 2 and 3.
It covers the alkanes from crude oil through cracking and combustion, the free radical mechanism of chlorination, then the alkenes, their electrophilic addition reactions and the polymers made from them.
Sample questions from Hydrocarbons
Answer each one closed book first, then open the answer.
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Alkanes, Fractional Distillation and Cracking
What property of the components allows fractional distillation to separate them?
Show the answer
Different boiling points -
Alkanes, Fractional Distillation and Cracking
What type of catalyst is used in catalytic cracking?
Show the answer
Zeolite catalyst -
Combustion of Alkanes and Pollutants
How are NOₓ pollutants formed in internal combustion engines?
Show the answer
Nitrogen and oxygen from the air react at the high temperatures inside the engine -
Combustion of Alkanes and Pollutants
What causes sulfur dioxide pollution from combustion of hydrocarbons?
Show the answer
Combustion of hydrocarbons that contain sulfur impurities -
Free Radical Chlorination of Alkanes
What is produced when a chlorine molecule undergoes homolytic fission?
Show the answer
Two chlorine radicals (Cl•) -
Free Radical Chlorination of Alkanes
Why do propagation steps form a chain reaction?
Show the answer
The radical produced in one step is a reactant in the next step, regenerating radicals to continue the reaction -
Alkenes: Structure, Bonding and Electrophilic Addition
What type of species attacks the carbon-carbon double bond in alkenes during addition reactions?
Show the answer
Electrophiles -
Alkenes: Structure, Bonding and Electrophilic Addition
What type of intermediate is formed during the electrophilic addition mechanism?
Show the answer
A carbocation
The 7 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Alkanes, Fractional Distillation and Cracking | Saturated hydrocarbons, separating crude oil by boiling point, and thermal and catalytic cracking. | 16 |
| Combustion of Alkanes and Pollutants | Complete and incomplete combustion, the pollutants formed, and catalytic converters and flue gas desulfurisation. | 16 |
| Free Radical Chlorination of Alkanes | Initiation, propagation and termination, and why the reaction gives a mixture of products. | 15 |
| Alkenes: Structure, Bonding and Electrophilic Addition | The C=C double bond as a centre of high electron density, and the mechanism of electrophilic addition. | 20 |
| Markovnikov's Rule and Carbocation Stability | Primary, secondary and tertiary carbocations, and predicting the major product. | 12 |
| Addition Polymers and Repeating Units | Drawing the repeating unit from a monomer, and the monomer from a polymer. | 9 |
| Properties and Uses of Polyalkenes | Why polyalkenes are unreactive, the problems that causes, and how they are disposed of. | 30 |
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 A-Level Chemistry Active Recall Guide
Every topic, not just this one. 2,442 questions with their answers.