Halogenoalkanes, Alcohols and Organic Analysis | AQA A-Level Chemistry (7405)
Halogenoalkanes, Alcohols and Organic Analysis
- 175 questions
- 12 subtopics
- Organic chemistry, examined on Paper 2
- Paper 2 and Paper 3
Halogenoalkanes, alcohols and organic analysis is examined on Papers 2 and 3.
It covers nucleophilic substitution and elimination in halogenoalkanes, the ozone problem, then the production, classification and oxidation of alcohols, and the spectroscopic methods used to identify a compound.
Sample questions from Halogenoalkanes, Alcohols and Organic Analysis
Answer each one closed book first, then open the answer.
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Nucleophilic Substitution of Halogenoalkanes
In the reaction of a halogenoalkane with cyanide ions, what is the organic product?
Show the answer
A nitrile -
Effect of Bond Enthalpy on Reaction Rate
Why do iodoalkanes react faster than chloroalkanes in nucleophilic substitution reactions?
Show the answer
The C-I bond has a lower bond enthalpy than the C-Cl bond, so it is easier to break. -
CFCs and Ozone Depletion
What role do chlorine atoms play in the decomposition of ozone?
Show the answer
They catalyse the decomposition of ozone -
Industrial Production of Alcohols
Why is fractional distillation necessary to obtain ethanol from the fermentation mixture?
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Ethanol is mixed with water and other impurities in the fermentation mixture, and fractional distillation separates components based on their different boiling points -
Classification and Oxidation of Alcohols
What is the product when a primary alcohol is oxidised under distillation conditions?
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An aldehyde -
Distinguishing Aldehydes and Ketones
What colour change occurs when Fehling's solution gives a positive result with an aldehyde?
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Blue solution changes to brick-red precipitate -
Test-Tube Reactions for Functional Groups
What observation indicates a positive test when Tollens' reagent reacts with an aldehyde?
Show the answer
Colourless solution produces a silver mirror -
Mass Spectrometry and Molecular Formula
How would you calculate relative atomic mass from a mass spectrum showing isotopic abundances?
Show the answer
Multiply each isotopic mass by its relative abundance, sum these values, then divide by the total abundance (usually 100).
The 12 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Nucleophilic Substitution of Halogenoalkanes | Why the carbon-halogen bond is polar, the mechanism, and the products with each nucleophile. | 18 |
| Effect of Bond Enthalpy on Reaction Rate | Why iodoalkanes hydrolyse fastest, and why bond enthalpy matters more than polarity here. | 10 |
| Elimination Reactions and Competing Mechanisms | The conditions that favour elimination over substitution, and the mechanism. | 14 |
| CFCs and Ozone Depletion | How chlorine radicals from CFCs catalyse ozone breakdown, and the equations for the cycle. | 12 |
| Industrial Production of Alcohols | Hydration of ethene and fermentation, the conditions for each, and comparing them. | 15 |
| Biofuels and Carbon Neutrality | What makes a fuel a biofuel, what carbon neutral means, and why the claim is disputed. | 17 |
| Classification and Oxidation of Alcohols | Primary, secondary and tertiary alcohols, the oxidising agent, and the products from each. | 23 |
| Distinguishing Aldehydes and Ketones | Fehling's and Tollens' reagents, and the observations that separate the two. | 10 |
| Elimination of Water from Alcohols | Dehydration to an alkene, the catalyst and conditions, and the mechanism. | 10 |
| Test-Tube Reactions for Functional Groups | The reagents and observations that identify alkenes, alcohols, aldehydes and carboxylic acids. | 16 |
| Mass Spectrometry and Molecular Formula | The molecular ion peak, fragmentation, and finding relative molecular mass from a spectrum. | 16 |
| Infrared Spectroscopy, Functional Groups and Global Warming | Identifying functional groups from absorption wavenumbers, the fingerprint region, and the link to the greenhouse effect. | 14 |
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.