Buffers

Question 1

What is a buffer?

Answer 1

Aqueous solution consisting of a mixture of either a weak acid and its conjugate base (salt) or a weak base and its conjugate acid (salt). Consists of acid and base in equilibrium

Question 2

Aha happens to the pH of a buffer when small amounts of strong acid (or base) is added to it?

Answer 2

It changes very slightly

Question 3

What is a acidic buffer?

Answer 3

A weak acid and its conjugate base

CH3C00H + H20 to CH3C00- + H30+

Question 4

What happens when a strong base is added to a acidic buffer?

Answer 4

The weak acid (AH) will give up its proton in order to transform the base (OH-) into water and the conjugate base.
pH will change only slightly

Question 5

What happens when a strong acid is added to a acidic buffer?

Answer 5

The weak base (A-) will react with the H30 from the strong acid to form the weak acid (HA) and water.
pH will only change slightly

Question 6

What is buffer capacity?

Answer 6

Ability of the buffer to resist changes in pH on addition of acid (or base)

Question 7

What does buffer capacity depend on?

Answer 7

The polarity of the buffer. Buffer capacity increases as polarity of the buffer solution (C0) increase.
Buffer capacity depends on the pH of the solution

Question 8

When is maximum buffer capacity obtained?

Answer 8

When pH of the solution is equal to the pKa of the buffer