Account for the following

Ethylamine is soluble in water whereas aniline is not

Account for the following.

Amines are more basic than amides.

Account for the following

Although amino group is$\mathrm{o} –$ and $\mathrm{p} –$ directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of $\mathrm{m} –$nitroaniline. 

Arrange the following

In increasing order of solubility in water, ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2, ({\mathrm{C}}_2{\mathrm{H}}_5{)}_2\mathrm{NH}, {\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NH}}_2$

Arrange the followings in increasing order of basic strength.

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2, {\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NHCH}}_3, \mathrm{p}-\mathrm{Cl}-{\mathrm{C}}_6{\mathrm{H}}_4-{\mathrm{NH}}_2$.

Arrange the following in decreasing order of basic strength in gas phase. $\left({\mathrm{C}}_2{\mathrm{H}}_5\right){\mathrm{NH}}_2, ({\mathrm{C}}_2{\mathrm{H}}_5{)}_2\mathrm{NH}, ({\mathrm{C}}_2{\mathrm{H}}_5{)}_3\mathrm{N} \mathrm{and} {\mathrm{NH}}_3$.

Arrange the following in increasing order of boiling point

${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH}, ({\mathrm{CH}}_3{)}_2\mathrm{NH}, {\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NH}}_2$

Arrange the following in decreasing order of the pK_b values

${\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NH}}_2, {\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NHCH}}_3 ,({\mathrm{C}}_2{\mathrm{H}}_5{)}_2\mathrm{NH} \mathrm{and} {\mathrm{CH}}_3{\mathrm{NH}}_2$