The correct order of `K_(b)` value of following is `(C_(2)H_(5))_(2)overset(..)(N)H,NH_(3)overset(..)(N)(C_(2)H_(5))_(3)`

Point out the correct decreasing order of pK_(b) values of following amines C_(2)H_(5)NH_(2),C_(6)H_(5)NHCH_(3),(C_(2)H_(5))_(2)NHandC_(6)H_(5)NH_(2)

IUPAC name of C_(2) H_(5)-overset(CH_(3))overset(|)(C H) - NH_(2) is

The increasing order of K _(b) for the following compounds will be: H _(2) N- overset(NH) overset(||) underset(I)(C)-NH_(2), CH_(3) -overset(NH) overset(||)underset(II) (C)-NH_(2), underset(III)(CH_(2))-NH_(2)

For the given four structures , I to IV, which of the following is correct ? underset((I))(C_(2)H_(5)-overset(CH_(3))overset(|)(C)H-C_(3)H_(7)) underset((II))(CH_(3)-overset(O)overset(P)(C)-overset(CH_(3))overset(|)(C)H-C_(2)H_(5)) underset((III))(CH_(3)-overset(O)overset(P)(C ) -overset(C_(2)H_(5))overset(|)(C ) H -C_(2)H_(5)) underset((IV))(C_(2)H_(5)-overset(CH_(3))overset(|)(C)H-C_(2)H_(5))