What's in a Medicine? | OCR A-Level Chemistry B (Salters) (H433)
What's in a Medicine?
- 235 questions
- 17 subtopics
- The ten storylines, examined across all three papers
- Component 01, Component 02 and Component 03
The storyline that carries the oxygen-containing functional groups and the practical organic work: alcohols and phenols and their reactions, preparing and purifying a solid and a liquid product, green chemistry, elimination, and identifying a compound by mass spectrometry and infrared..
It covers formulae of oxygen-containing homologous series, primary, secondary and tertiary alcohols, the acidity of phenol compared with alcohols and carboxylic acids, the iron(III) chloride test and esterifying a phenol, esterification and oxidising primary, secondary and tertiary alcohols, dehydration, halogenation and planning a two-step synthesis, preparing aspirin, filtering under reduced pressure and recrystallisation, thin layer chromatography, Rf values and percentage yield, reflux and distillation in an organic preparation, washing, drying and redistilling a liquid product, the aims of green chemistry and atom economy, catalysts, renewable feedstocks and measuring greenness, elimination reactions, the molecular ion and fragment ions, identifying a compound from its fragments and the M+1 peak, how infrared absorption works and the characteristic absorptions and reading a spectrum, the fingerprint region and combining techniques.
Sample questions from What's in a Medicine?
Answer each one closed book first, then open the answer.
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Formulae of oxygen-containing homologous series
Give the molecular formula of ethanoic anhydride.
Show the answer
Ethanoic anhydride is (CH₃CO)₂O, molecular formula C₄H₆O₃. -
The acidity of phenol compared with alcohols and carboxylic acids
What is the name of the salt formed when phenol reacts with sodium hydroxide?
Show the answer
Sodium phenoxide is formed. -
Esterification and oxidising primary, secondary and tertiary alcohols
State the oxidising mixture used to oxidise alcohols.
Show the answer
Potassium dichromate(VI) solution acidified with dilute sulfuric acid is used. -
Preparing aspirin, filtering under reduced pressure and recrystallisation
Give two advantages of filtration under reduced pressure over gravity filtration.
Show the answer
It is much faster, and it leaves the solid drier because air is pulled through the crystals. -
Reflux and distillation in an organic preparation
Why are anti-bumping granules added before refluxing?
Show the answer
They provide nucleation sites for small, steady bubbles and so prevent violent, uneven boiling. -
The aims of green chemistry and atom economy
Write the expression used to calculate atom economy.
Show the answer
Atom economy = (Mᵣ of the desired product ÷ sum of the Mᵣ values of all reactants) × 100. -
Elimination reactions
State the two sets of conditions that bring about the elimination of water from an alcohol.
Show the answer
Passing the vapour over heated aluminium oxide, or heating the alcohol under reflux with concentrated sulfuric acid. -
Identifying a compound from its fragments and the M+1 peak
Ethanoic acid gives an M⁺ peak at m/z 60 and a strong peak at m/z 45. What has been lost?
Show the answer
A methyl group of mass 15 has been lost, since 60 − 15 = 45.
The 17 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Formulae of oxygen-containing homologous series | Recall questions on the functional groups and general formulae of carboxylic acids, esters, anhydrides, aldehydes and ketones. | 22 |
| Primary, secondary and tertiary alcohols | Recall questions on what defines each class, how many hydrogens sit on the hydroxyl carbon, and classifying a named alcohol. | 20 |
| The acidity of phenol compared with alcohols and carboxylic acids | Recall questions on why phenol is a stronger acid than an alcohol but weaker than a carboxylic acid, and its reaction with sodium hydroxide. | 12 |
| The iron(III) chloride test and esterifying a phenol | Recall questions on the neutral iron(III) chloride test, and why a phenol needs an anhydride or acyl chloride rather than a carboxylic acid. | 11 |
| Esterification and oxidising primary, secondary and tertiary alcohols | Recall questions on the acid-catalysed ester equilibrium, the dichromate colour change, and what distillation and reflux each give from a primary alcohol. | 15 |
| Dehydration, halogenation and planning a two-step synthesis | Recall questions on the conditions for dehydration and for making a haloalkane, and on the order of steps in a two-step route. | 11 |
| Preparing aspirin, filtering under reduced pressure and recrystallisation | Recall questions on the aspirin preparation, Buchner filtration, and each stage of a recrystallisation and why it is done that way. | 13 |
| Thin layer chromatography, Rf values and percentage yield | Recall questions on the TLC plate and tank, locating colourless spots, calculating an Rf value, and why a recrystallised yield is low. | 13 |
| Reflux and distillation in an organic preparation | Recall questions on what reflux achieves, anti-bumping granules, why the apparatus is never sealed, and where the thermometer bulb sits in a distillation. | 9 |
| Washing, drying and redistilling a liquid product | Recall questions on using a separating funnel, washing with sodium hydrogencarbonate, choosing and removing a drying agent, and why the product is redistilled. | 15 |
| The aims of green chemistry and atom economy | Recall questions on preventing rather than treating waste, the atom economy expression, and why it differs from percentage yield. | 11 |
| Catalysts, renewable feedstocks and measuring greenness | Recall questions on why a catalytic route is greener, renewable feedstocks, co-products against by-products, and what can actually be measured. | 12 |
| Elimination reactions | Recall questions on what is lost and what is formed, dehydrating an alcohol, why two alkenes can result, and eliminating from a haloalkane. | 19 |
| The molecular ion and fragment ions | Recall questions on what the horizontal axis shows, what the molecular ion peak gives, and why fragment peaks appear below it. | 11 |
| Identifying a compound from its fragments and the M+1 peak | Recall questions on the common fragment masses, working a structure out from a spectrum, and what causes the M+1 peak. | 15 |
| How infrared absorption works and the characteristic absorptions | Recall questions on why each bond absorbs at its own wavenumber, and the ranges for O-H, C=O, C≡N, N-H and C=C. | 13 |
| Reading a spectrum, the fingerprint region and combining techniques | Recall questions on identifying a compound from its absorptions, following an oxidation by infrared, and why infrared is combined with other techniques. | 13 |
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
OCR A-Level Chemistry B (Salters) Active Recall Guide
Every topic, not just this one. 3,430 questions with their answers.