Revise later
SpaceTo flip
If confident
All Flashcards
Define buffer capacity.
A measure of how much acid or base a buffer can absorb before its pH changes significantly.
What determines buffer pH?
The ratio of the concentration of the conjugate base to the concentration of the weak acid, [A-]/[HA].
What is the key factor for buffer capacity?
The magnitudes (actual concentrations) of the weak acid and its conjugate base.
Relate moles to buffer capacity.
Buffer capacity is directly related to the number of moles of the weak acid and conjugate base. More moles = greater capacity!
What does a 'stronger buffer' mean?
A buffer that is more resistant to pH changes upon the addition of acid or base.
Compare a 5M acetic acid/5M sodium acetate buffer to a 0.05M acetic acid/0.05M sodium acetate buffer regarding buffer capacity.
Both have the same pH, but the 5M/5M buffer has a much higher buffer capacity.
What is the difference between buffer pH and buffer capacity?
Buffer pH is determined by the ratio of [A-]/[HA], while buffer capacity is determined by the magnitudes of [A-] and [HA].
What is the effect of halving the moles of both weak acid and conjugate base in a buffer?
The buffer capacity decreases; it becomes less resistant to pH changes.
What happens when a small amount of strong acid is added to a buffer solution?
The added $H^+$ reacts with the conjugate base to form the weak acid, minimizing the change in pH.
What is the effect of doubling the concentrations of both the weak acid and conjugate base?
The buffer capacity increases, making it more resistant to pH changes.