---
title: "A student titrates a \\(25.00 \\text{ mL}\\) sample of a monoprotic weak acid, \\(\\text{HA(aq)}\\), with standardized \\(0.100 \\text{ M NaOH(aq)}\\) using a clean buret. The student fills the buret but fails to notice an air bubble trapped in the tip below the stopcock prior to recording the initial volume reading. During the titration, the air bubble is completely displaced by \\(\\text{NaOH(aq)}\\) and exits the tip before the endpoint is reached. Which of the following best explains how this error affects the calculated molarity of \\(\\text{HA(aq)}\\)?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/119683/"
date_modified: "2026-08-21T08:12:02+00:00"
---

# A student titrates a \(25.00 \text{ mL}\) sample of a monoprotic weak acid, \(\text{HA(aq)}\), with standardized \(0.100 \text{ M NaOH(aq)}\) using a clean buret. The student fills the buret but fails to notice an air bubble trapped in the tip below the stopcock prior to recording the initial volume reading. During the titration, the air bubble is completely displaced by \(\text{NaOH(aq)}\) and exits the tip before the endpoint is reached. Which of the following best explains how this error affects the calculated molarity of \(\text{HA(aq)}\)?

A student titrates a \(25.00 \text{ mL}\) sample of a monoprotic weak acid, \(\text{HA(aq)}\), with standardized \(0.100 \text{ M NaOH(aq)}\) using a clean buret. The student fills the buret but fails to notice an air bubble trapped in the tip below the stopcock prior to recording the initial volume reading. During the titration, the air bubble is completely displaced by \(\text{NaOH(aq)}\) and exits the tip before the endpoint is reached. Which of the following best explains how this error affects the calculated molarity of \(\text{HA(aq)}\)?

- **A.** The calculated molarity will be too high because the presence of the air bubble causes the recorded initial buret volume to be lower than the true volume of liquid in the buret barrel.
- **B.** The calculated molarity will be too high because the recorded volume of \(\text{NaOH(aq)}\) dispensed is greater than the volume actually delivered to the analyte solution, resulting in an overestimate of the moles of \(\text{HA}\) present.
- **C.** The calculated molarity will be too low because the air bubble displaces a portion of the \(\text{NaOH(aq)}\) solution in the tip, reducing the effective concentration of the titrant reaching the analyte.
- **D.** The calculated molarity will be too low because fewer moles of \(\text{NaOH}\) are delivered to the flask than what corresponds to the difference between the final and initial buret readings, causing the student to calculate fewer moles of \(\text{HA}\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119683/*