H-A Is an Acid with a PKa of 4

question 40

Multiple Choice

H-A is an acid with a pKa of 4.5.Which of the following statements about an aqueous solution of H-A is true?

• A)At pH = 4.5,the solution contains much more H-A than.A^-.
• B)At pH = 4.5,the solution contains much more A^- than H-A.
• C)At pH- 3.5,the solution contains about 90% A^- and 10% H-A.
• D)At pH = 6.5,the solution contains about 80% A^{- and 20% H-A}.
• E)At pH = 5.5,the solution contains about 90% A^- and 10% H-A.

---

Definitions:

Cortical

Relating to the outer layer of the cerebrum or cortex, involved in complex brain functions such as memory and consciousness.

Echolocation

A biological sonar used by several kinds of animals, such as bats and dolphins, to navigate and locate prey by emitting sound waves and listening for echoes.

High-Pitched Sounds

Sounds that have a frequency at the higher end of the human hearing range.

Olfaction

The sense of smell, a chemical sensing system detecting odors or scents, crucial for taste perception and hazard detection.