12.2.2 - Buffer solutions

Question 1

Explain what is meant by a buffer solution.

Answer 1

Solutions that resist slight changes in pH
When small amounts of acid, base and water are added.

Question 2

What are 2 ways that buffer solutions can be made?

Answer 2

Weak acid + conjugate base
weak base + conjugate acid

Question 3

Why do buffer solutions maintain a constant pH?

Answer 3

The concentration of the weak acid and its conjugate base remain fairly constant.

Question 4

What is the Henderson - Hasselbalch equation for calculating the pH of buffer solutions?

Answer 4

H+ = Ka x acid/salt

Question 4

What is the buffer maintained in our blood?

Answer 4

Carbonic acid - hydrogencarbonate buffer

Question 5

One of the systems controlling the pH of blood is the carbonic acid-hydrogencarbonate
buffer system.
Explain how this buffer system helps to control the pH of blood when extra
carbon dioxide is present due to strenuous exercise.

Answer 5

carbon dioxide dissolves in the blood to form carbonic acid.
So equilibrium moves right to produce more Hydrogen ions.
Large excess of hydrogencarbonate ions combine with the H+ to form carbonic acid and control pH.