Ch21 Buffers + Neutralisation

Question 1

What is a buffer solution?

Answer 1

• Buffer solution is a system containing two components that can minimise changes in pH when small amounts of an acid/base added.
• Component 1 = weak acid (only partially ionises with eqm) to remove added alkali (not strong acid as it would completely ionise)
• Component 2 = its conjugate base to remove any added acid

Eventually the 2 components would be used up, so solution loses its buffering ability

Question 2

Explain the method of preparing a weak acid buffer solution from a weak acid and its salt (calculated amount)

Answer 2

Question 3

Explain the method of making a buffer solution by partial neutralisation of an acid:

Answer 3

Question 4

How do buffers work is an acid/alkali is added? Explain which direction the eqm would shift?

Answer 4

Question 5

How is the pH over which buffer solution calculated?

Answer 5

Question 6

How is the pH of buffer solution calculated mathematically

Answer 6

Question 7

Which buffer system operates in the human blood?

Answer 7

The carbonic acid - hydrogen carbonate buffer system (H2CO3 / HCO3-)

Question 8

What is the blood’s normal healthy pH:

Answer 8

7.40

Question 9

What happens if the human blood exceeds/goes below its normal pH

Answer 9

• Below pH 7.35 = acidosis can develop causing fatigue, shortness of breath + death
• Above pH 7.45 = alkalosis can develop causing muscle spasms, light headedness, nausea.

Question 10

How does the buffer system in human blood react to addition of acid and addition of alkali? Which direction does eqm shift and what happens to the ions/products/reactants

Answer 10