Core Organic Chemistry | OCR A-Level Chemistry A (H432)
Core Organic Chemistry
- 116 questions
- 9 subtopics
- Module 4: Core organic chemistry
- Component 02 and Component 03
The three families that carry most of the reactions: alkanes and radical substitution, alcohols and their oxidation, and haloalkanes with nucleophilic substitution, ending in the CFC and ozone story and how analytical techniques are combined..
It covers alkanes: bonding, shape and boiling points, combustion of alkanes and their reaction with halogens, the radical substitution mechanism and its limitations, alcohols: polarity, solubility and classification, oxidation, dehydration and substitution reactions of alcohols, hydrolysis of haloalkanes and comparing the rates, nucleophilic substitution and carbon-halogen bond strength, cFCs, radicals and the catalytic destruction of ozone and combining analytical techniques to identify a compound.
Sample questions from Core Organic Chemistry
Answer each one closed book first, then open the answer.
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Alkanes: bonding, shape and boiling points
What is the shape around each carbon atom in an alkane?
Show the answer
Tetrahedral. -
Combustion of alkanes and their reaction with halogens
Why is carbon monoxide produced from incomplete combustion dangerous to humans?
Show the answer
It is a toxic gas that binds to haemoglobin, preventing oxygen transport in the blood. -
The radical substitution mechanism and its limitations
Why does the combination of two radicals terminate the chain reaction?
Show the answer
Because no new radicals are produced, so the chain cannot continue. -
Alcohols: polarity, solubility and classification
Why are short-chain alcohols soluble in water?
Show the answer
They can form hydrogen bonds with water molecules through their hydroxyl group. -
Oxidation, dehydration and substitution reactions of alcohols
How many [O] are required to oxidise a primary alcohol to a carboxylic acid?
Show the answer
Two [O] are required. -
Hydrolysis of haloalkanes and comparing the rates
When comparing hydrolysis rates of haloalkanes using silver nitrate, what happens to the halide ion released?
Show the answer
The halide ion reacts with silver ions in solution. -
Nucleophilic substitution and carbon-halogen bond strength
In the mechanism for nucleophilic substitution of a primary haloalkane, where does the first curly arrow originate and where does it point?
Show the answer
The first curly arrow originates from the lone pair on the hydroxide ion and points to the carbon atom. -
CFCs, radicals and the catalytic destruction of ozone
What is the equation for the first step of the catalytic destruction of ozone by chlorine radicals?
Show the answer
Cl• + O₃ → ClO• + O₂
The 9 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Alkanes: bonding, shape and boiling points | Recall questions on saturation and σ-bonding, the tetrahedral shape and its angle, and why boiling point rises with chain length and falls with branching. | 12 |
| Combustion of alkanes and their reaction with halogens | Recall questions on the products of complete and incomplete combustion, why carbon monoxide is dangerous, and the conditions under which alkanes react with halogens. | 8 |
| The radical substitution mechanism and its limitations | Recall questions on initiation, propagation and termination, why ultraviolet light is needed, and why the reaction is of limited use in synthesis. | 19 |
| Alcohols: polarity, solubility and classification | Recall questions on why alcohols are polar and hydrogen bond, why short-chain alcohols dissolve, their low volatility, and primary, secondary and tertiary classification. | 8 |
| Oxidation, dehydration and substitution reactions of alcohols | Recall questions on the conditions that give an aldehyde rather than a carboxylic acid, why tertiary alcohols resist oxidation, dehydration, and substitution to a haloalkane. | 16 |
| Hydrolysis of haloalkanes and comparing the rates | Recall questions on the product of hydrolysis by aqueous alkali, and on the silver nitrate experiment that compares the rates for the different halogens. | 9 |
| Nucleophilic substitution and carbon-halogen bond strength | Recall questions on the mechanism step by step, and on why the C-F bond is hardest and the C-I bond easiest to break. | 12 |
| CFCs, radicals and the catalytic destruction of ozone | Recall questions on the homolytic fission of a CFC by ultraviolet light, the two steps of the catalytic cycle, why the chlorine radical is a catalyst, and how the science shaped policy. | 20 |
| Combining analytical techniques to identify a compound | Recall questions on what infrared, mass spectrometry, elemental analysis, NMR and simple test-tube reactions each contribute, and why one technique alone is not enough. | 12 |
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 sections
OCR A-Level Chemistry A Active Recall Guide
Every section, not just this one. 1,913 questions with their answers.