8.8 Buffer Solutions

Question 1

What is a buffer solution?

Answer 1

One which resists changes in pH when small amounts of acid or alkali are added.

Question 2

What does a buffer solution contain?

Answer 2

Two components and must always contain something to react with any acid added and something to react with any base added.

Question 3

What is an acidic buffer solution?

Answer 3

A solution of a weak acid (HA) and the salt/conjugate base of that weak acid.

Question 4

What is the equilibrium that exists in the acidic buffer solution?

Answer 4

HA (aq) H+ (aq) + A- (aq)

Question 5

What happens if acid is added to the buffer solution?

Answer 5

A- (aq) + H+(aq) —–> HA (aq)

Question 6

What happens if alkali is added to the buffer solution?

Answer 6

HA(aq) + OH-(aq) —–> A-(aq) + H2O (l)

Question 7

Why do small changes in the concentration of HA and A- not change the position of the original equilibrium?

Answer 7

Because large amounts of HA and A- are present and hence the pH remain approximately constant.

Question 8

What is a basic buffer solution?

Answer 8

Contains a weak base and the salt of that weak base.