At Westonci.ca, we connect you with the answers you need, thanks to our active and informed community. Connect with professionals on our platform to receive accurate answers to your questions quickly and efficiently. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

Phenylephrine is a nasal decongestant and is the active ingredient in Sudafed, which contains phenylephrine hydrochloride (PEHCL). The conjugate acid (PEH+) of phenylphrine has a pKa = 5.5. At a physiological pH of 7.4. what is the ratio of concentrations, [PE]/[PEH+]?

Sagot :

Answer:

The ratio of concentrations is 79.4

Explanation:

Using Henderson-Hasselbalch equation we can solve the [PE]/[PEH+] ratio:

pH = pKa + log [A-] / [HA]

Where pH is 7.4

pKa of the phenylphrine is 5.5

[A-] is the weak base = [PE]

And [HA] is the conjugate acid [PEH+]

Replacing:

7.4 = 5.5 + log [PE] / [PEH+]

1.9 = log [PE] / [PEH+]

79.4 = [PE] / [PEH+]

The ratio of concentrations is 79.4