CCEA A-Level Chemistry 1110
Formulae, Equations and Amounts of Substance
Atomic Structure
Bonding
Intermolecular Forces and Structure
Shapes of Molecules and Ions
Redox
The Halogens
Acid-Base Titrations
Qualitative Tests
Formulae and Amounts of a Substance
Nomenclature and Isomerism in Organic Chemistry
Alkanes
Alkenes
Halogenoalkanes
Alcohols
Infrared Spectroscopy
Energetics
Kinetics
Equilibrium
Group II Elements and Their Compounds
Lattice Enthalpy, Entropy and Free Energy
Rates of Reaction
Equilibrium and Acid-Base Equilibria
Isomerism
Aldehydes and Ketones
Carboxylic Acids
Derivatives of Carboxylic Acids
Aromatic Chemistry
Spectroscopy and Chromatography
Volumetric Analysis
Transition Metals
Electrode Potentials
Amines
Amides and Polymers
Amino Acids and Proteins
Chemistry in Medicine
Aspirin: synthesis and analysis
- 3 things to know
- Unit A2 2
Overview
Recall questions on the synthesis from salicylic acid with ethanoic anhydride and why that reagent is chosen, the catalyst and the equation, purification by recrystallisation and checking purity by melting point, why aspirin is supplied as the sodium salt, determining its concentration by titration with phenolphthalein, and why the solution must be fresh.
What you need to know
Answer each one before you reveal it.
Write the equation for the synthesis of aspirin from salicylic acid and ethanoic anhydride
What catalyst is used in the synthesis of aspirin?
Questions from this subtopic
Each one with the model answer underneath.
- 1
From what is aspirin synthesised?
Model answer
Salicylic acid, also called 2-hydroxybenzoic acid.
- 2
What reagent converts salicylic acid to aspirin?
Model answer
Ethanoic anhydride.
- 3
Write the equation for the synthesis.
Model answer
C₆H₄(OH)COOH + (CH₃CO)₂O → C₆H₄(OCOCH₃)COOH + CH₃COOH.
- 4
Why is ethanoic anhydride used rather than ethanoic acid?
Model answer
It is far more reactive, so the reaction goes to completion rather than reaching an equilibrium.
- 5
Why is ethanoic anhydride preferred to ethanoyl chloride industrially?
Model answer
It is cheaper, less readily hydrolysed and does not release corrosive hydrogen chloride.
- 6
What catalyst is used?
Model answer
A few drops of concentrated sulfuric or phosphoric acid.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Chemistry in Medicine, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.