Question

In order to arrange the compound in order to decreasing basicity amine dimethyl amine methyl amine tri methyl amine

Answer 1

Answer:

This is an interesting question…

We have to look at two factors here..hydration energy and steric hinderance..

As we know by theory of the inductive effect the trialkyl version should be more basic simply because of the increased +I..but this is NOT OBSERVED..

This is mainly because when we compare the basic natures in water ..we also have to consider hydration energy of the protinated amine..this is pretty low for the trialkyl version..and highest for the monoalkyl one..

But the dialkyl one has enough +I groups ie two alkyl groups as well as a pretty high hydration energy..

This makes it the most basic out of the three..

Answer 2

Answer:

Order:

In non aqueous mediums:

tri methyl amine > dimethyl amine > methyl amine

reason: Stable cations with increasing number of carbon directly attached to N.

In aqueous mediums:

tri methyl amine < dimethyl amine < methyl amine

reason: Hydrogen bonds