Final answer:
Aniline has a higher pKb value than methylamine due to its phenyl group. Ethylamine is soluble in water but aniline is not due to hydrogen bonding. Methylamine reacts with ferric chloride in water to precipitate hydrated ferric oxide.
Step-by-step explanation:
(i) The pKb value is a measure of the strength of a base. Aniline is a stronger base than methylamine, which means it has a higher pKb value. This is because aniline has a phenyl group attached to the nitrogen atom, which increases its electron density and makes it more willing to accept a hydrogen ion.
(ii) Ethylamine is soluble in water because it can form hydrogen bonds with water molecules. Aniline, on the other hand, is not very soluble in water because it cannot form strong hydrogen bonds with water due to the presence of the phenyl group.
(iii) Methylamine reacts with ferric chloride in water to form hydrated ferric oxide precipitate. This reaction occurs because methylamine can act as a ligand and form complex ions with the ferric chloride, leading to the precipitation of hydrated ferric oxide.