-1
$\begingroup$

My book states that nitrogen-containing rings are generally referred to as bases, and that under acidic conditions they can each bind an $\ce{H+}$. However, does this increase or decrease the concentration of $\ce{OH-}$ ions in an aqueous solution and why?

$\endgroup$
1
$\begingroup$

Brønsted (or Brønsted–Lowry) acid-base theory says a base will accept a proton from water. You can't take a H+ ion away from H2O without 'leaving' an OH-. The pKa of piperidine is 11.22, which means it is a fairly strong base. Apparently, you are asking what happens when you add a base to an aqueous acidic solution. The pH goes up. Meaning the pOH goes down. This is just another way of saying that [OH-] increases.

$\endgroup$
0
$\begingroup$

What one needs to understand first when dealing with acids and bases is that:

A substance can be acidic, if its constituent molecules have the capability to either donate an $\ce{H+ (like HCl)}$ or accept an $\ce{OH- (like H3BO3)}$ from water ,ie effectively have an electron deficient center

Similarly,

A base is a substance whose constituent molecules can donate an $\ce{OH- (like NaOH)}$ or abstract $\ce{H+ (like RO- ) }$ from water,ie effectively have an electron rich center,Now when Nitrogen is bonded to other atoms

[ up to 3 other atoms which are not electron deficient themselves (like an $\ce{NO2 or -CF3 group}$), or capable of conjugating the lone pair of nitrogen into themselves(like in anilene) ,above which it wont be able to show basic character longer as it cant form any more than 4 bonds ]

It still retains its lone pair,therby making itself an elecrton rich species; Hence retaining its ability to donate the lone pair to an electron deficient centre or abstract an $\ce{H+}$ from water,rendering a basic medium.

Note that nowhere in any of these processes has there been the involvement of an $\ce{OH-}$ group. Although technically, while in aqueous medium compounds with nitrogen abstract a proton from water and release an $\ce{OH-}$ therby increasing the $\ce{[OH-]}$

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.