Chapter 13

You have prepared a solid crystalline compound which you think is \(N\)-phenylethanamide (literature m.pt. \(\left.=114^{\circ} \mathrm{C}\right)\) and its m.pt. range is 108 \(110^{\circ} \mathrm{C}\). Draw three possible conclusions from this result.

You have obtained a sample of a white crystal. line compound which you think is benzoic acic (literature m.pt. \(=121^{\circ} \mathrm{C}\) ) and its m.pt. range is found to be \(120-128,{ }^{\circ} \mathrm{C}\). Draw three possible con clusions from this result.

You have carried out a synthetic procedure which results in a mixture of 2 -nitroaniline (literature \(\mathrm{m} . \mathrm{pt}=92{ }^{\circ} \mathrm{C}\) ) and 4-nitroaniline (literature m.pt. \(\left.=148^{\circ} \mathrm{C}\right)\). Purification by recrystallisation is said to separate the two isomers and your sample, when mixed with pure 4-nitroaniline, has a m.pt. range \(147-148^{\circ} \mathrm{C}\). What can you conclude?