Different types of chemical bases
In module 04 the different types of bases were already named:
- Organic molecules
Normally those organic substances that contain Nitrogen where that Nitrogen atom contains a free electron pair.
Think of amines and the amino acids.
- Negative ions
In principle all negative ions can catch, take up H+ ions, so they are bases, wether weak or strong.
Some are exstremely weak, like Cl-.
Then the basic character is only theory. In reality this is nothing.
- Some positive ions
Cathions normally are acids, as we have seen. But if they are polyprotonic, polyvalent, so they can donate more than one proton, then we are close to this possibility:
For example, if the 3+ hydrated Aluminium ion (Al(H2O)63+) has donated one proton, then Al(OH)(H2O)52+) was formed.
This is a positiveionthat is able to take back that proton, and thus react as a base.
The same particle can of course also continue with donating (and form Al(OH)2(H2O)4+ ).
After all the particle can donate as well as capture, so it is amphoteric.
- Neutral molecules
Like, for example: ammonia and water (where water is amphoteric)