What is a Buffer?
- A weak acid and its conjugate base together ○ Conjugate base usually present within a salt
- A weak base and its conjugate acid together
- The purpose of a buffer is to resist changes in pH when either H+ or OH- are added
Write the Reaction of…
Adding a Strong Acid to a Buffer
- 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
○ Pick the strongest acid
■ Always choose H+ ion if present ○ Pick the strongest base
■ Always choose OH- ion if present
■ Do not pick a base that forms a strong acid
Adding a Strong Base
- Adding a strong base to a weak acid buffer system → the strong base will take proton from the weak acid