Preparation of phenylamine/aniline This is the procedure I carried out in class:


Reduction of nitrobenzene by using tin and $\ce{HCl}$ acid
After the completion of the reaction, $\ce{NaOH}$ added to neutralize excess acid and dissolve any $\ce{Sn(OH)2}$
Steam distillation is carried out to obtain suspension of phenylamine
Salting carried out where $\ce{NaCl}$ salt is added. Aqueous layer discarded
Solvent extraction: dry ether added and mixture shaken vigorously. Aqueous layer discarded
Distillation under reduced pressure carried out and solid phenylamine left in flask


My questions:


Instead of carrying out distillation under reduced pressure at the end of the procedure to remove the ether, could I have just carried out simple distillation?
Why is steam distillation suitable in part 3? Could I have used vacuum distillation here?
Instead of carrying out distillation under reduced pressure at the end of the procedure to remove the ether, could I have just carried out simple distillation?


You could have performed any procedure to remove the solvent:


Simple distillation  - This would be slower than what you did and could overheat the undistilled aniline causing decomposition.
Vacuum distillation - This is what you did, perhaps even on a special apparatus called a rotary evaporator. This method is still a distillation, even if your product was not distilled. Something was distilled.
Evaporation on a hot plate (or steam bath)- 



  Why is steam distillation suitable in part 3? Could I have used vacuum distillation here?


Steam distillation is suitable because the aniline is already in an aqueous suspension. If do vacuum distillation, you would need to


Separate the aniline from the aqueous mixture (extract with ether)
Remove the ether (simple distillation or reduced pressure distillation)
Vacuum distil the aniline


If you look at what you did, it is the same steps in a different order:


Distil the aniline 
Separate the aniline from the aqueous mixture (extract with ether)
Remove the ether (simple distillation or reduced pressure
distillation)


Either is probably suitable. In the end, the steam distillation is easier and less hazardous than the full-blown vacuum distillation you would need.