I hope this post fits into the category!
I have become bit confused about pKa values and the level of dissociation of acids. For instance if we have acetic acid it has a pKa value of 4.76, so the degree of dissociation of this acetic acids as function of pH would look this:
Uploaded with ImageShack.us
Btw what do you call this kind of diagram in English? In Danish we call it a "Bjerrum Diagram"
So this means that acetic acid would be almost 100 % dissociated at pH 7. But it is supposed to be a weak acid right, so how can this be?
So if you have some water (pH = 7) and you then add some acetic acid, the pH value will drop, but so will the dissociation rate of the acid. So the acid kind of "undissociates" itself by lowering the pH value?
And can you say that for all acids or bases, that they can be 100 % dissociated as long as the pH value is right?
And finally the lower the pKa value the stronger the acid is, right? So what about a base that has got a pKa value of around 11, is that a strong base? And how to find out?
I know there are a lot of questions and that they are probably quite fundamental, but this is something I have not been able to make sense of as of yet, so some answers would be most appreciated!