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What is the difference between buffer capacity and buffer effectiveness?
Buffer capacity is the amount of acid or base a buffer can neutralize. Buffer effectiveness is how well the buffer resists pH changes.
Compare how strong acids/bases and weak acids/bases affect buffer formation.
Strong acids/bases do NOT form buffers with their conjugates because their conjugates are too weak. Only weak acid/base pairs can create buffers.
How does a buffer neutralize added acid (H+)?
The conjugate base (A-) reacts with H+ to form the weak acid (HA), preventing a large increase in [H+].
How does a buffer neutralize added base (OH-)?
The weak acid (HA) reacts with OH- to form the conjugate base (A-) and water (H2O), preventing a large increase in [OH-].
What are the steps to preparing a buffer solution?
- Choose a weak acid/base system with a pKa close to the desired pH. 2. Mix the weak acid/base with its conjugate in comparable concentrations. 3. Adjust the pH with strong acid or base, if necessary.
What is a buffer solution?
A solution that resists changes in pH upon addition of small amounts of acid or base.
Define a weak acid.
An acid that only partially dissociates into its ions in a solution.
Define a conjugate base.
The species that remains after an acid has donated a proton.
What is maximum buffer capacity?
The point where a buffer resists pH changes the best, occurring when [weak acid] = [conjugate base].
Define buffer effectiveness.
How well a buffer resists changes in pH.
What is a spectator ion?
An ion that exists in the same form on both the reactant and product sides of a chemical reaction. It does not affect equilibrium.