Synthetic routes and problem solvingEdexcel International A Level Chemistry: Mind map

Exam questions on Synthetic routes and problem solving

1. 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
2. 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
3. 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