BUFFERS

Question 1

• What is a buffer?

Answer 1

• A buffer is a solution which can resist changes in pH when a small amount of acid or base is added
• They are designed to keep [H+] almost unchanged, as then the pH remains almost constant

Question 2

• What is an acidic buffer?

Answer 2

• An acidic buffer is made of a weak acid and a soluble salt of that acid. It maintains a pH below 7.

Question 3

• How do the acid and salt dissociate in an acidic buffer?

Answer 3

• The weak acid only partially dissociates, so equilibrium lies to the LHS
• The salt of that weak acid fully dissociates, so the equilibrium lies to the RHS

Question 4

• What happens if too much H+ and OH- are added to a buffer?

Answer 4

• Buffers can only cope when a small amount of H+ and OH- are added. If too much is added, the buffer can get saturated

Question 5

• What is a basic buffer?

Answer 5

• A basic buffer is made of a weak base and a soluble salt of that base. It maintains a pH above 7.