A woman is brought into the emergency room experiencing nausea and vomiting. She is also hyperventilating. She says that she ing

Question

3 years ago

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A woman is brought into the emergency room experiencing nausea and vomiting. She is also hyperventilating. She says that she ing

ested a bottle of aspirin about two hours earlier. Aspirin (acetylsalicylic acid) is converted to salicylic acid in the stomach. Assuming 100% conversion to salicylic acid.
Required:
Calculate the percentage of protonated and unprotonated forms of salicylic acid in her stomach, given a pH of 2.0 for the stomach.

Chemistry

1 answer:

Keith_Richards [23] · Answer 1 · 2022-07-24T14:00:37+03:00

Answer:

Protonated form: 96.87%

Unprotonated form: 3.13%

Explanation:

To find the percentage of protoned and unprotoned forms of salicylic acid we must use Henderson-Hasselbalch equation:

pH = pKa + log [A⁻] / [HA]

<em>Where pKa of salicylic acid is 3.49; [A⁻] is the unprotonated form and [HA]:</em>

<em />

2.0 = 3.49 + log [A⁻] / [HA]

0.03236 = [A⁻] / [HA] <em>(1)</em>

And as:

[A⁻] + [HA] = 100% <em>(2)</em>

Replacing (2) in (1):

0.03236 = 100 - [HA] / [HA]

0.03236 [HA] = 100 - [HA]

1.03236[HA] = 100

And [A⁻]:

[A⁻] = 100 - 96.87