What is a Buffer?
- A weak acid and its conjugate base is present in some form (usually within a salt)
- A weak base and its conjugate acid is present in form form (usually within a salt)
- A buffered solution/purpose of a buffer resists changes in pH when either H+ or OH- are added
Adding a Strong Acid
- Adding a strong acid to a weak acid buffer system → the strong acid will add its proton to the conjugate base
- List out major species
- Notes: water will always be a major species; strong acid will break up into its ions; a weak acid will remain whole)
- Consider candidates for acids → Pick the strongest acid
- Always choose H+ ion if present
- Consider candidates for bases → Pick the strongest base
- Always choose OH- ion if present
- Do not pick a base that forms a strong acid
- List out major species
Adding a Strong Base
- Adding a strong base to a weak acid buffer system → the strong base will take proton from the weak acid