---
title: "A student studies the decomposition of hydrogen peroxide in an antimicrobial rinse at constant temperature. Under the experimental conditions, the reaction follows first-order kinetics.  \\(2\\text{H}_2\\text{O}_2\\text{(aq)} \\rightarrow 2\\text{H}_2\\text{O(l)} + \\text{O}_2\\text{(g)}\\)  | Time (min) | \\([\\text{H}_2\\text{O}_2]\\) (M) | |————|———————————-| | 0.0        | \\(0.800\\)                        | | 14.0       | \\(0.400\\)                        |  What is the concentration of \\(\\text{H}_2\\text{O}_2\\text{(aq)}\\) after \\(42.0\\text{ min}\\)?"
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url: "https://nerd-notes.com/ubq/119308/"
date_modified: "2026-08-19T12:39:44+00:00"
---

# A student studies the decomposition of hydrogen peroxide in an antimicrobial rinse at constant temperature. Under the experimental conditions, the reaction follows first-order kinetics.

\(2\text{H}_2\text{O}_2\text{(aq)} \rightarrow 2\text{H}_2\text{O(l)} + \text{O}_2\text{(g)}\)

| Time (min) | \([\text{H}_2\text{O}_2]\) (M) |
|————|———————————-|
| 0.0        | \(0.800\)                        |
| 14.0       | \(0.400\)                        |

What is the concentration of \(\text{H}_2\text{O}_2\text{(aq)}\) after \(42.0\text{ min}\)?

A student studies the decomposition of hydrogen peroxide in an antimicrobial rinse at constant temperature. Under the experimental conditions, the reaction follows first-order kinetics.

\(2\text{H}_2\text{O}_2\text{(aq)} \rightarrow 2\text{H}_2\text{O(l)} + \text{O}_2\text{(g)}\)

| Time (min) | \([\text{H}_2\text{O}_2]\) (M) |
|------------|----------------------------------|
| 0.0        | \(0.800\)                        |
| 14.0       | \(0.400\)                        |

What is the concentration of \(\text{H}_2\text{O}_2\text{(aq)}\) after \(42.0\text{ min}\)?

- **A.** \(0.0500\text{ M}\)
- **B.** \(0.100\text{ M}\)
- **C.** \(0.200\text{ M}\)
- **D.** \(0.400\text{ M}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119308/*