---
title: "A student divides a slurry containing equal amounts of \\(\\text{M(OH)}_2\\text{(s)}\\) into two samples. The student adds a small volume of concentrated \\(\\text{HNO}_3\\text{(aq)}\\) to one sample and the same volume of deionized water to the control. The metal remains in the +2 oxidation state. After stirring both samples for the same amount of time, the student filters the mixtures, dries and weighs the recovered solids, and determines the total moles of aqueous \\(\\text{M}^{2+}\\) in each filtrate.  Which experimental result would provide the strongest evidence that the metal hydroxide precipitate dissolved after the concentrated acid was added?"
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/119542/"
date_modified: "2026-08-19T12:55:14+00:00"
---

# A student divides a slurry containing equal amounts of \(\text{M(OH)}_2\text{(s)}\) into two samples. The student adds a small volume of concentrated \(\text{HNO}_3\text{(aq)}\) to one sample and the same volume of deionized water to the control. The metal remains in the +2 oxidation state. After stirring both samples for the same amount of time, the student filters the mixtures, dries and weighs the recovered solids, and determines the total moles of aqueous \(\text{M}^{2+}\) in each filtrate.

Which experimental result would provide the strongest evidence that the metal hydroxide precipitate dissolved after the concentrated acid was added?

A student divides a slurry containing equal amounts of \(\text{M(OH)}_2\text{(s)}\) into two samples. The student adds a small volume of concentrated \(\text{HNO}_3\text{(aq)}\) to one sample and the same volume of deionized water to the control. The metal remains in the +2 oxidation state. After stirring both samples for the same amount of time, the student filters the mixtures, dries and weighs the recovered solids, and determines the total moles of aqueous \(\text{M}^{2+}\) in each filtrate.

Which experimental result would provide the strongest evidence that the metal hydroxide precipitate dissolved after the concentrated acid was added?

- **A.** Compared with the control, the treated sample has a lower pH and contains more \(\text{NO}_3^-\text{(aq)}\), while the recovered solid mass is not measured.
- **B.** Compared with the control, the treated sample has greater conductivity and reaches a higher temperature during mixing, while aqueous \(\text{M}^{2+}\) is not measured.
- **C.** Compared with the control, the treated sample yields less recovered solid, but the measured moles of aqueous \(\text{M}^{2+}\) remain unchanged within experimental uncertainty.
- **D.** Compared with the control, the treated sample yields less recovered solid, and the measured increase in aqueous \(\text{M}^{2+}\) corresponds to the solid mass lost.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119542/*