---
title: "A student titrates a \\(25.00 \\text{ mL}\\) sample of an unknown monoprotic acid, \\(\\text{HA(aq)}\\), with a standardized \\(0.100 \\text{ M NaOH(aq)}\\) solution according to the following equation:  \\[ \\text{HA(aq)} + \\text{NaOH(aq)} \\rightarrow \\text{NaA(aq)} + \\text{H}_2\\text{O(l)} \\]  The student records the liquid levels in the buret before beginning the titration and at the equivalence point, as shown in the diagrams. Based on these data, what is the calculated molar concentration of \\(\\text{HA(aq)}\\) in the original sample?"
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url: "https://nerd-notes.com/ubq/119837/"
date_modified: "2026-08-21T08:12:45+00:00"
---

# A student titrates a \(25.00 \text{ mL}\) sample of an unknown monoprotic acid, \(\text{HA(aq)}\), with a standardized \(0.100 \text{ M NaOH(aq)}\) solution according to the following equation:

\[ \text{HA(aq)} + \text{NaOH(aq)} \rightarrow \text{NaA(aq)} + \text{H}_2\text{O(l)} \]

The student records the liquid levels in the buret before beginning the titration and at the equivalence point, as shown in the diagrams. Based on these data, what is the calculated molar concentration of \(\text{HA(aq)}\) in the original sample?

A student titrates a \(25.00 \text{ mL}\) sample of an unknown monoprotic acid, \(\text{HA(aq)}\), with a standardized \(0.100 \text{ M NaOH(aq)}\) solution according to the following equation:

\[ \text{HA(aq)} + \text{NaOH(aq)} \rightarrow \text{NaA(aq)} + \text{H}_2\text{O(l)} \]

The student records the liquid levels in the buret before beginning the titration and at the equivalence point, as shown in the diagrams. Based on these data, what is the calculated molar concentration of \(\text{HA(aq)}\) in the original sample?

![A vertical buret tube segment with black graduation lines on a white background. Major horizontal tick marks are labeled with integers increasing downward: 2 near the top, 3 in the middle, and 4 near the bottom. Between each integer, exactly 10 equal subdivisions are marked with shorter horizontal ticks, each representing 0.1 mL, with the 0.5 mL mark being intermediate in length. A concave liquid meniscus is shown between marks 2 and 3, with the bottom of the curve resting tangentially on the fifth subdivision tick below the 2 mark, exactly at 2.50 mL. Below the meniscus, the buret is filled with a uniform light gray shading representing the solution. A single label above reads Initial reading. No other markings, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787299965-ATmZCQ.jpg)

![A vertical buret tube segment with black graduation lines on a white background. Major horizontal tick marks are labeled with integers increasing downward: 22 near the top, 23 in the middle, and 24 near the bottom. Between each integer, exactly 10 equal subdivisions are marked with shorter horizontal ticks, each representing 0.1 mL, with the 0.5 mL mark being intermediate in length. A concave liquid meniscus is shown between marks 22 and 23, with the bottom of the curve resting tangentially on the fifth subdivision tick below the 22 mark, exactly at 22.50 mL. Below the meniscus, the buret is filled with a uniform light gray shading representing the solution. A single label above reads Final reading. No other markings, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-2-1787299965-R7L3Cg.jpg)

- **A.** \(0.0444 \text{ M}\)
- **B.** \(0.0600 \text{ M}\)
- **C.** \(0.0800 \text{ M}\)
- **D.** \(0.0900 \text{ M}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119837/*