Account for the following :
(i) Aniline does not give friedel crafts reaction
(ii) Ethylamine is solubelin water wheras aniline isnot
(iii) `Pk_(b)` of methyalmine is les than of aniline

Explanation

(i) Aniline being a lewis base reacts with lewis acid `AICI_(3)` to form as solt
`C_(6)H_(5)NH_(2)+AICI_(3)rarrC_(6)H_(5)N^(+)H_(2)AICI_(3)`
As a resutl N of aniline acquires + ve charge and hence it acts a strong deacitvating group for electrophilic substitution reaction . consequently anilne does not undergo friedn crafts reaction .
(ii) Ethylamine forms inter molecular H-bonding wiht water where as aniline larger is the hydorphobic part lkes is the extent of H Bonding hecne not soluble
(iii) As methyl group is electron donating group which increases the electrons density hence more basic wheres the electons density on aniline decreases due to resonance hence made PKb value