Give the decreasing orderof solubility of the following in`H_(2)O`:
(I)`PhNH_(2),(II)Et_(2)NH,(III)EtNH_(2)`
(b)Give the decreasing order to boiling point of the followings:
(I) `EtOH`, (II) `Me_2NH` (II) ` EtNH_2`
c. Ethanoamine can form two differnt interamolecular `H-`bonds. Write their structrues. Which form is more stable ?

Explanation

a. `(III) gt (II) gt (I) (1^@ gt 2^@` amine gt arylamine ). Arylamine is least soluble since it has a large hydrophobic part (phenyl group ).
b. `(I) gt (III) (II) ("alcohol" gt 1^@ gt 2^@` amine )
c. (I)
`(I) gt (II)` . Since ` EN` of `O gt N`, its `H-`bond to N is stronger than the H-bond from N to O.