Ok, I'm studying acid and base buffers at the moment. What I can't understand is that, with an acid buffer (e.g. sodium ethanoate and ethanoic acid), why does the base react only with the undissociated acid (i.e. the ethanoic acid)? If the base was a strong base (e.g. sodium hydroxide, wouldn't it dissociate in the water readily, causing the OH- ions to react with the small amount of H+ ions created from the dissociated ethanoic acid (I know this is quite small, but wouldn't it still count)?
/sci/, lend me your cognitive thought!
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Anonymous2007-11-12 20:41
I dont have a good background on chemisty, but i think thats what a Acid-Base reaction is, hydrolised acid reacting with a base resulting in H2O and a salt. Im probably just retarded, stating a obviose fact but thats all i remmember.
>>1
The OH- does react with H+ (H3O+) in solution.
But, since you have disrupted the buffer equilibrium by adding more base, by le chatlier's principle, more acid will dissociate so that the equilbrium is regained. This will keep happening until all the OH- is absorbed, provided you don't exceed the buffer capacity.
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Anonymous2007-11-14 5:22
Just consider the pKa and pKw.
14 compared to about 4. Which do you think is going to be the dominant species dissociated at equilibrium?
Le Chatelier's principle is lies btw, and only works sometimes.