---
title: "A student analyzing proton transfer in a water sample represents the reaction as follows.  \\(\\text{H}_2\\text{PO}_4^-\\text{(aq)} + \\text{H}_2\\text{O(l)} \\rightleftharpoons \\text{H}_3\\text{O}^+\\text{(aq)} + \\text{HPO}_4^{2-}\\text{(aq)}\\)  Which choice correctly identifies both the acid and its conjugate base and the base and its conjugate acid, with the species in each pair listed in that order for the forward reaction?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/119344/"
date_modified: "2026-08-19T12:39:53+00:00"
---

# A student analyzing proton transfer in a water sample represents the reaction as follows.

\(\text{H}_2\text{PO}_4^-\text{(aq)} + \text{H}_2\text{O(l)} \rightleftharpoons \text{H}_3\text{O}^+\text{(aq)} + \text{HPO}_4^{2-}\text{(aq)}\)

Which choice correctly identifies both the acid and its conjugate base and the base and its conjugate acid, with the species in each pair listed in that order for the forward reaction?

A student analyzing proton transfer in a water sample represents the reaction as follows.

\(\text{H}_2\text{PO}_4^-\text{(aq)} + \text{H}_2\text{O(l)} \rightleftharpoons \text{H}_3\text{O}^+\text{(aq)} + \text{HPO}_4^{2-}\text{(aq)}\)

Which choice correctly identifies both the acid and its conjugate base and the base and its conjugate acid, with the species in each pair listed in that order for the forward reaction?

- **A.** Acid/conjugate base: \(\text{H}_3\text{O}^+\text{(aq)}\), \(\text{H}_2\text{O(l)}\); base/conjugate acid: \(\text{HPO}_4^{2-}\text{(aq)}\), \(\text{H}_2\text{PO}_4^-\text{(aq)}\)
- **B.** Acid/conjugate base: \(\text{H}_2\text{PO}_4^-\text{(aq)}\), \(\text{HPO}_4^{2-}\text{(aq)}\); base/conjugate acid: \(\text{HPO}_4^{2-}\text{(aq)}\), \(\text{H}_2\text{PO}_4^-\text{(aq)}\)
- **C.** Acid/conjugate base: \(\text{H}_3\text{O}^+\text{(aq)}\), \(\text{H}_2\text{O(l)}\); base/conjugate acid: \(\text{H}_2\text{O(l)}\), \(\text{H}_3\text{O}^+\text{(aq)}\)
- **D.** Acid/conjugate base: \(\text{H}_2\text{PO}_4^-\text{(aq)}\), \(\text{HPO}_4^{2-}\text{(aq)}\); base/conjugate acid: \(\text{H}_2\text{O(l)}\), \(\text{H}_3\text{O}^+\text{(aq)}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119344/*