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