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title: "A student performs a titration experiment to determine the molar mass of an unknown solid monoprotic acid, \\(\\text{HA}\\). A \\(0.420\\text{ g}\\) sample of \\(\\text{HA}\\) is dissolved in \\(50.0\\text{ mL}\\) of distilled water and titrated with standardized \\(0.100\\text{ M }\\text{NaOH(aq)}\\). Before the titration begins, an air bubble is trapped in the buret tip below the stopcock. During the titration, the air bubble is completely expelled as the solution is delivered, and the titration is stopped precisely at the equivalence point. Which of the following best explains how the presence and loss of the air bubble affects the recorded volume of \\(\\text{NaOH(aq)}\\) delivered and the resulting calculated molar mass of \\(\\text{HA}\\)?"
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url: "https://nerd-notes.com/ubq/123767/"
date_modified: "2026-09-28T12:30:13+00:00"
---

# A student performs a titration experiment to determine the molar mass of an unknown solid monoprotic acid, \(\text{HA}\). A \(0.420\text{ g}\) sample of \(\text{HA}\) is dissolved in \(50.0\text{ mL}\) of distilled water and titrated with standardized \(0.100\text{ M }\text{NaOH(aq)}\). Before the titration begins, an air bubble is trapped in the buret tip below the stopcock. During the titration, the air bubble is completely expelled as the solution is delivered, and the titration is stopped precisely at the equivalence point. Which of the following best explains how the presence and loss of the air bubble affects the recorded volume of \(\text{NaOH(aq)}\) delivered and the resulting calculated molar mass of \(\text{HA}\)?

A student performs a titration experiment to determine the molar mass of an unknown solid monoprotic acid, \(\text{HA}\). A \(0.420\text{ g}\) sample of \(\text{HA}\) is dissolved in \(50.0\text{ mL}\) of distilled water and titrated with standardized \(0.100\text{ M }\text{NaOH(aq)}\). Before the titration begins, an air bubble is trapped in the buret tip below the stopcock. During the titration, the air bubble is completely expelled as the solution is delivered, and the titration is stopped precisely at the equivalence point. Which of the following best explains how the presence and loss of the air bubble affects the recorded volume of \(\text{NaOH(aq)}\) delivered and the resulting calculated molar mass of \(\text{HA}\)?

- **A.** The recorded volume of \(\text{NaOH(aq)}\) delivered is less than the actual volume, resulting in a calculated molar mass of \(\text{HA}\) that is too low because the calculated number of moles of acid is less than the actual number of moles.
- **B.** The recorded volume of \(\text{NaOH(aq)}\) delivered is less than the actual volume, resulting in a calculated molar mass of \(\text{HA}\) that is too high because the calculated number of moles of acid is less than the actual number of moles.
- **C.** The recorded volume of \(\text{NaOH(aq)}\) delivered is greater than the actual volume, resulting in a calculated molar mass of \(\text{HA}\) that is too low because the calculated number of moles of acid is greater than the actual number of moles.
- **D.** The recorded volume of \(\text{NaOH(aq)}\) delivered is greater than the actual volume, resulting in a calculated molar mass of \(\text{HA}\) that is too high because the calculated number of moles of acid is greater than the actual number of moles.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123767/*