Organic Chemistry | AQA GCSE Combined Science Trilogy Chemistry, Higher tier (8464)
Organic Chemistry
- 84 questions
- 5 subtopics
- Chemistry Paper 2
- Chemistry Paper 2
Organic Chemistry is examined in Chemistry Paper 2.
It covers crude oil, hydrocarbons and alkanes, fractional distillation and petrochemicals, properties of hydrocarbons, cracking, and testing alkenes with bromine water and why cracking is useful, and equations for it.
Sample questions from Organic Chemistry
Answer each one closed book first, then open the answer.
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Crude oil, hydrocarbons and alkanes
Which type of compound makes up most of crude oil?
Show the answer
Hydrocarbons. -
Crude oil, hydrocarbons and alkanes
What does a molecular formula such as C₃H₈ tell you about an alkane?
Show the answer
It gives the number of carbon atoms and the number of hydrogen atoms in one molecule, but not how they are joined. -
Fractional distillation and petrochemicals
What is meant by feedstock in the petrochemical industry?
Show the answer
Feedstock is the raw material fed into the industry and used to make other chemicals. -
Fractional distillation and petrochemicals
What is a homologous series?
Show the answer
A homologous series is a family of similar compounds that share the same general formula and have similar chemical properties. -
Properties of hydrocarbons
How does viscosity change as hydrocarbon molecules get larger?
Show the answer
Viscosity increases, so the liquid flows less easily. -
Properties of hydrocarbons
Write the balanced equation for the complete combustion of methane.
Show the answer
CH₄ + 2O₂ → CO₂ + 2H₂O. -
Cracking, and testing alkenes with bromine water
State one thing that catalytic cracking and steam cracking have in common.
Show the answer
Both require the hydrocarbon to be vaporised and heated to a high temperature so that its molecules break apart. -
Cracking, and testing alkenes with bromine water
Cracking one large alkane produces a smaller alkane and an alkene. Explain why both can be formed from one molecule.
Show the answer
The molecule breaks into two smaller ones, and there are not enough hydrogen atoms for both to be saturated, so one of them contains a carbon–carbon double bond.
The 5 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Crude oil, hydrocarbons and alkanes | Crude oil as a finite resource formed from ancient plankton, hydrocarbons and why crude oil is a mixture, the alkanes and their general formula CₙH₂ₙ₊₂, the molecular formulae of methane, ethane, propane and butane, and what molecular and displayed formulae show. | 18 |
| Fractional distillation and petrochemicals | Separating crude oil into fractions of similar-sized molecules by fractional distillation, fuels such as petrol, diesel and kerosene, petrochemical feedstock for solvents, lubricants, polymers and detergents, why carbon forms so many compounds, homologous series, and how the fractionating column works. | 17 |
| Properties of hydrocarbons | How boiling point, viscosity and flammability depend on molecular size, what viscosity and flammability mean, complete combustion of hydrocarbons to carbon dioxide and water as an exothermic oxidation, balanced combustion equations for methane, ethane and propane, and choosing hydrocarbons as fuels. | 17 |
| Cracking, and testing alkenes with bromine water | Cracking as the thermal decomposition of large hydrocarbons into smaller molecules, catalytic cracking and steam cracking and their conditions, the alkanes and unsaturated alkenes produced, and the bromine water test, which turns from orange to colourless with an alkene. | 17 |
| Why cracking is useful, and equations for it | Why small hydrocarbons are in demand and large fractions are cracked, the uses of alkenes, balancing cracking equations such as C₁₀H₂₂ to C₈H₁₈ and C₂H₄, and how modern life depends on hydrocarbons. | 15 |
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 Combined Science Trilogy Chemistry, Higher tier Active Recall Guide
Every topic, not just this one. 1,222 questions with their answers.