---
title: "A student prepares a buffer solution using a weak monoprotic acid, \\(\\text{HA}\\) (\\(K_a = 1.0 \\times 10^{-5}\\)), and its conjugate base, \\(\\text{A}^-\\). The \\(\\text{pH}\\) of the final solution is adjusted to \\(6.00\\) at \\(25\\ ^\\circ\\text{C}\\). Based on this information, which of the following is closest to the percentage of the acid species present in the deprotonated form, \\(\\text{A}^-\\)?"
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url: "https://nerd-notes.com/ubq/123821/"
date_modified: "2026-09-28T12:30:26+00:00"
---

# A student prepares a buffer solution using a weak monoprotic acid, \(\text{HA}\) (\(K_a = 1.0 \times 10^{-5}\)), and its conjugate base, \(\text{A}^-\). The \(\text{pH}\) of the final solution is adjusted to \(6.00\) at \(25\ ^\circ\text{C}\). Based on this information, which of the following is closest to the percentage of the acid species present in the deprotonated form, \(\text{A}^-\)?

A student prepares a buffer solution using a weak monoprotic acid, \(\text{HA}\) (\(K_a = 1.0 \times 10^{-5}\)), and its conjugate base, \(\text{A}^-\). The \(\text{pH}\) of the final solution is adjusted to \(6.00\) at \(25\ ^\circ\text{C}\). Based on this information, which of the following is closest to the percentage of the acid species present in the deprotonated form, \(\text{A}^-\)?

- **A.** \(9.1\%\)
- **B.** \(91\%\)
- **C.** \(99\%\)
- **D.** \(99.9\%\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123821/*