15.2 Buffered solutions

•  Buffered solutions — resists changes in pH when small quantities of either a strong acid (H+ ions) or strong base (OH–) are added.
• Examples of Buffer in Blood: H2CO3 and HCO3-
• What are characteristics of a buffer?

  1. Absorbs acids and bases produced in biologic reaction without alterations to pH
  2. Contain a weak acid and its salt
  3. EX From blood buffers: H+ is absorbed by HCO3-, and OH- is absorbed by H2CO3.
• Buffering is possible at any pH, and it is based on choice of appropriate components used for any buffer
• A buffer solution must contain a weak acid and its conjugate base. A buffer can be made by dissolving a weak acid and a salt containing the conjugate base, or dissolving a weak base and a salt containing the conjugate acid in the same solution. A buffer can also be made by adding a strong base to partially neutralize a solution of a weak acid or by adding a strong acid to partially neutralize a solution of a weak base. Both NaOH and KOH are strong bases.