---
title: "A student titrates a sample of an unknown acid with \\(0.100\\text{ M NaOH(aq)}\\) using a \\(\\text{pH}\\) sensor. The resulting titration curve is shown below.  Based on the titration curve, which of the following claims about the unknown acid is correct?"
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url: "https://nerd-notes.com/ubq/119799/"
date_modified: "2026-08-21T08:12:22+00:00"
---

# A student titrates a sample of an unknown acid with \(0.100\text{ M NaOH(aq)}\) using a \(\text{pH}\) sensor. The resulting titration curve is shown below.

Based on the titration curve, which of the following claims about the unknown acid is correct?

A student titrates a sample of an unknown acid with \(0.100\text{ M NaOH(aq)}\) using a \(\text{pH}\) sensor. The resulting titration curve is shown below.

Based on the titration curve, which of the following claims about the unknown acid is correct?

![A 2D line graph displaying a titration curve with bare axes and light grid lines. The horizontal axis is labeled 'Volume of 0.100 M NaOH added (mL)' with values from 0 to 40 marked at increments of 5. The vertical axis is labeled 'pH' with values from 0 to 14 marked at increments of 2. A single solid black curve begins at (0, 2.0), rises slightly through a flat buffer plateau centered at (7.5, 3.5), rises sharply through a first vertical inflection region centered at (15.0, 5.5), continues through a second flat buffer plateau centered at (22.5, 7.2), rises sharply through a second vertical inflection region centered at (30.0, 10.0), and levels off horizontally at a pH of approximately 12.0 near 40 mL. No other curves, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787299942-OHcDv8.jpg)

- **A.** The acid is diprotic because the curve displays two steep increases in \(\text{pH}\), indicating two successive equivalence points.
- **B.** The acid is diprotic because the initial \(\text{pH}\) of the solution before adding titrant is greater than \(1.0\).
- **C.** The acid is monoprotic because the buffer region between \(0\text{ mL}\) and \(15.0\text{ mL}\) neutralizes all acidic protons in the sample.
- **D.** The acid is monoprotic because the second equivalence point occurs at a \(\text{pH}\) greater than \(7.0\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119799/*