Synthetic routes and problem solvingEdexcel International A Level Chemistry: Flashcards
What these 14 flashcards ask
- How do you plan a multi-step synthesis?
- Which reagent adds one carbon to a haloalkane chain?
- How is a nitrile converted into an amine?
- How is a nitrile converted into a carboxylic acid?
- How do you calculate overall yield for a multi-step route?
- What are the conditions for converting benzene into nitrobenzene?
- What reagents reduce nitrobenzene to phenylamine?
- Which technique oxidises a primary alcohol fully to a carboxylic acid?
- Which technique stops oxidation at the aldehyde?
- Why do OH, COOH and NH₂ groups raise water solubility?
- What is the difference between hazard and risk?
- Why is a fume cupboard used?
- What control measure is used for flammable liquids?
- Why must cyanide solutions never be mixed with acid?
Exam questions on Synthetic routes and problem solving
- Compound X has the structure HOCH₂CH=CHCOOH (4-hydroxybut-2-enoic acid). A student has not seen this compound before and is asked to predict its properties from the functional groups it contains.Predict whether X is more or less soluble in water than but-2-ene, and explain your answer.2 marks
- A chemist wants to make propylamine, CH₃CH₂CH₂NH₂, from bromoethane in two steps. In step 1 bromoethane is converted into a nitrile. In step 2 the nitrile is converted into propylamine.A student suggests making propylamine in one step by heating bromoethane with excess ammonia in ethanol. Explain why this cannot work.2 marks
- A three-step route converts benzene into N-phenylethanamide, C₆H₅NHCOCH₃. Step 1 converts benzene into nitrobenzene (yield 80%). Step 2 converts nitrobenzene into phenylamine (yield 75%). Step 3 converts phenylamine into N-phenylethanamide using ethanoyl chloride (yield 90%). A student starts with 15.6 g of benzene. Relative formula masses: benzene 78.0; N-phenylethanamide 135.0.Calculate the overall percentage yield and the mass of N-phenylethanamide the student obtains.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).