Buffer Soloutions Flashcards
What is a buffer
Minimises changes in ph
Buffers do not
Stop the change in ph just resist it
What are the two types of buffers
Acidic & basic
What is an acidic buffer?
A buffer solution that resists small changes in ph in order to keep the solution below ph 7.
What are acidic buffers made from
A weak acid & its salt
Where does the equilibrium lie for a weak acid
Weak acids dissociate weakly so equilibrium lies strongly to the lest.
Where does the equilibrium lie for salts.
Salts dissociate strongly so equilibrium lies well over to the left.
What happens when we add H to a an acidic buffer?
The H ions react with the salts ions in solution.
There is a high conc of these from the salt.
So more of the acid is produced which means equilibrium shifts to the left.
What happens when we add a base to an acid buffer?
The oh ions react with the h ions in solution.
There is a low conc of these however they can be reproduces from a high conc of the acid to counter act the change in concentration.
Equilibrium shifts to the right to replace the reacted H ions
What are basic buffers?
Basic buffers resist the change in ph in order to keep the solution above ph 7.
What are basic buffers made of
A weak base & IRS salt
Where does the equilibrium lie for the weak base?
Weak base produce very little of ions so equilibrium lies well over to the left
Where does equilibrium lie for the weak base salt
The salt dissociates fully so the equilibrium lies well over to the right.
What happens when we add more of ions to the basic buffer
The old ions react wit the weak base ions in solution.
There is a high come of these from the salt.
More of the salt and water is produced which means equilibrium shifts to the left.
What happens when we add H ions to the basic buffers.
The H ions react with oh ions in solution.
There is a low concentration of these however they can be reproduced to form a high conc of the base and water to counteract the change.
Equilibriomshiers to the right to replace the reached oh ions.
