---
title: "A student titrates a \\(25.0 \\text{ mL}\\) sample of an unknown diprotic acid, \\(\\text{H}_2\\text{A(aq)}\\), with a standardized \\(0.200 \\text{ M } \\text{NaOH(aq)}\\) solution according to the balanced equation below:  \\[\\text{H}_2\\text{A(aq)} + 2\\,\\text{NaOH(aq)} \\rightarrow \\text{Na}_2\\text{A(aq)} + 2\\,\\text{H}_2\\text{O(l)}\\]  The student reaches the second equivalence point after adding exactly \\(30.0 \\text{ mL}\\) of the \\(\\text{NaOH(aq)}\\) titrant. What is the molar concentration of the \\(\\text{H}_2\\text{A(aq)}\\) solution?"
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url: "https://nerd-notes.com/ubq/119951/"
date_modified: "2026-08-21T08:21:21+00:00"
---

# A student titrates a \(25.0 \text{ mL}\) sample of an unknown diprotic acid, \(\text{H}_2\text{A(aq)}\), with a standardized \(0.200 \text{ M } \text{NaOH(aq)}\) solution according to the balanced equation below:

\[\text{H}_2\text{A(aq)} + 2\,\text{NaOH(aq)} \rightarrow \text{Na}_2\text{A(aq)} + 2\,\text{H}_2\text{O(l)}\]

The student reaches the second equivalence point after adding exactly \(30.0 \text{ mL}\) of the \(\text{NaOH(aq)}\) titrant. What is the molar concentration of the \(\text{H}_2\text{A(aq)}\) solution?

A student titrates a \(25.0 \text{ mL}\) sample of an unknown diprotic acid, \(\text{H}_2\text{A(aq)}\), with a standardized \(0.200 \text{ M } \text{NaOH(aq)}\) solution according to the balanced equation below:

\[\text{H}_2\text{A(aq)} + 2\,\text{NaOH(aq)} \rightarrow \text{Na}_2\text{A(aq)} + 2\,\text{H}_2\text{O(l)}\]

The student reaches the second equivalence point after adding exactly \(30.0 \text{ mL}\) of the \(\text{NaOH(aq)}\) titrant. What is the molar concentration of the \(\text{H}_2\text{A(aq)}\) solution?

- **A.** \(0.0600 \text{ M}\)
- **B.** \(0.100 \text{ M}\)
- **C.** \(0.120 \text{ M}\)
- **D.** \(0.240 \text{ M}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119951/*