---
title: "A student standardizes an  \\(\\text{HCl(aq)}\\) solution of unknown concentration by titrating a \\(25.00 \\text{ mL}\\) sample with a standardized \\(0.100 \\text{ M}\\) \\(\\text{NaOH(aq)}\\) solution according to the equation below.  \\[ \\text{HCl}(aq) + \\text{NaOH}(aq) \\rightarrow \\text{NaCl}(aq) + \\text{H}_2\\text{O}(l) \\]  Before filling the buret with the \\(\\text{NaOH(aq)}\\) solution, the student rinses the buret with deionized water but fails to rinse it with the \\(0.100 \\text{ M}\\) \\(\\text{NaOH(aq)}\\) titrant solution, leaving residual water inside the buret barrel. Which of the following best explains how this error affects the calculated molarity of \\(\\text{HCl(aq)}\\)?"
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url: "https://nerd-notes.com/ubq/121479/"
date_modified: "2026-08-23T05:04:47+00:00"
---

# A student standardizes an 
\(\text{HCl(aq)}\) solution of unknown concentration by titrating a \(25.00 \text{ mL}\) sample with a standardized \(0.100 \text{ M}\) \(\text{NaOH(aq)}\) solution according to the equation below.

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

Before filling the buret with the \(\text{NaOH(aq)}\) solution, the student rinses the buret with deionized water but fails to rinse it with the \(0.100 \text{ M}\) \(\text{NaOH(aq)}\) titrant solution, leaving residual water inside the buret barrel. Which of the following best explains how this error affects the calculated molarity of \(\text{HCl(aq)}\)?

A student standardizes an 
\(\text{HCl(aq)}\) solution of unknown concentration by titrating a \(25.00 \text{ mL}\) sample with a standardized \(0.100 \text{ M}\) \(\text{NaOH(aq)}\) solution according to the equation below.

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

Before filling the buret with the \(\text{NaOH(aq)}\) solution, the student rinses the buret with deionized water but fails to rinse it with the \(0.100 \text{ M}\) \(\text{NaOH(aq)}\) titrant solution, leaving residual water inside the buret barrel. Which of the following best explains how this error affects the calculated molarity of \(\text{HCl(aq)}\)?

- **A.** The calculated molarity will be too high because the residual water dilutes the \(\text{NaOH(aq)}\), requiring a larger volume of titrant to reach the equivalence point.
- **B.** The calculated molarity will be too low because the residual water dilutes the \(\text{NaOH(aq)}\), decreasing the concentration of titrant that reacts in the flask.
- **C.** The calculated molarity will be too low because the added water increases the total volume in the flask, leading the student to divide by an erroneously large volume of solution.
- **D.** The calculated molarity will be unaffected because the number of moles of \(\text{HCl}\) originally present in the analyte flask does not change.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121479/*