pH and Buffers

What is the approximate pH range required for proteins in human blood to function correctly?

• 6.80 – 7.20

• 7.00 – 7.10

• 7.35 – 7.45

• 7.50 – 7.60

Which combination of substances is essential for forming an effective buffer solution?

• A strong acid and its conjugate base

• A strong base and its conjugate acid

• A weak acid and its conjugate base

• A weak base and a strong acid

When a strong acid (H+) is added to a buffer solution containing a weak acid (HA) and its conjugate base (A-), how does the buffer system primarily respond to maintain pH stability?

• The weak acid (HA) dissociates further to consume the added H+.

• The conjugate base (A-) reacts with the added H+ to form more weak acid (HA).

• The added H+ directly combines with water to form H3O+, which is then neutralized by the weak acid.

• The buffer solution precipitates the added H+ ions, removing them from the solution.

For a buffer solution to be most effective at resisting pH changes, what is the ideal relationship between its pH and the pKa of its weak acid component?

• The pH should be significantly lower than the pKa.

• The pH should be significantly higher than the pKa.

• The pH should be approximately equal to the pKa.

• The pH and pKa values are unrelated to buffer effectiveness.