Answer:
The 99.68% of the aspirin is present in the neutral form
Explanation:
Aspirin, Acetylsalicylic acid, is a weak acid with pKa = 3.5
Using Henderson-Hasselbalch equation:
pH = pKa + log [A⁻] / [HA]
<em>Where [A⁻] is the ionized form and HA the neutral form of the acid</em>
<em />
Replacing with a pH of stomach of 1.0:
1.0 = 3.5 + log [A⁻] / [HA]
-2.5 = log [A⁻] / [HA]
3.16x10⁻³ = [A⁻] / [HA] <em>(1)</em>
<em />
A 100% of aspirin is = [A⁻] + [HA]
100 = [A⁻] + [HA] <em>(2)</em>
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Replacing (2) in (1)
3.16x10⁻³ = 100 - [HA] / [HA]
3.16x10⁻³[HA] = 100 - [HA]
1.00316 [HA] = 100
[HA] = 99.68%
<h3>The 99.68% of the aspirin is present in the neutral form</h3>
