Phenylephrine (PE, See the Structure Below) Is a Nasal Decongestant

question 28

Multiple Choice

Phenylephrine (PE, see the structure below) is a nasal decongestant and is the active ingredient in Sudafed, which contains phenylephrine hydrochloride (PEHCl) . This conjugate acid of phenylephrine (PEH^) has a pK_a  5.5. At a physiological pH of 7.4, what is the ratio of concentrations, [PE]/[PEH^]?

• A)6.7
• B)0.01
• C)0.14
• D)79
• E)21

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Definitions:

Abdomen

The part of the body that lies between the chest and pelvis, containing most of the digestive system organs and often referred to as the belly.

Pregnancy

The condition of being pregnant, involving the development of a fetus in a woman's uterus.

Erectile Tissue

Specialized tissue that can become erect when filled with blood, found in the penis, clitoris, and nipples.

Homologous

Relating to or derived from a similar origin, especially referring to structures that have the same evolutionary background but may serve different functions.