Question

The problem statement, all variables and given/known data

Group#1: Buffer pH = 4.00

Group#2: Buffer pH = 4.35

Group#3: Buffer pH = 4.70

Group#4: Buffer pH = 5.00

Group#5: Buffer pH = 5.30

Group#6: Buffer pH = 5.60

1. Explain which group should havethe BEST OPTIMAL BUFFER (see choices above).

2. Explain which group has a buffer that has the HIGHEST BUFFERING CAPACITY AGAINST NaOH.

3. Explain which group has a buffer that has the HIGHEST BUFFERING CAPACITY AGAINST HCl.

4. Is the best optimal buffer the same as the buffer that has the HIGHEST buffer capacity againstNaOH? Explain your reasoning.

5. Is the best optimal buffer the same as the buffer that has the HIGHEST buffer capacity against HCl? Explain your reasoning.

Answer 1

Buffers are compounds that resist changes in pH. Buffering capacity= Moles of acid or base added in buffers solution / change in solution's pH. The greater the buffering capacity, the greater the quantity of acid or base which must be incorporated with a material to alter the pH. I would think that the highest buffering capacity against NaOH would be the highest pH, the highest buffering capacity against HCl would be the lowest pH. pka of HCl is -4, pkb of NaOH is 0.2.