---
title: "The decomposition of hydrogen peroxide is represented by the following equation.  \\(2\\text{H}_2\\text{O}_2\\text{(aq)} \\rightarrow 2\\text{H}_2\\text{O(l)} + \\text{O}_2\\text{(g)}\\)  A student performs three trials at the same temperature using the same initial amount and concentration of \\(\\text{H}_2\\text{O}_2\\text{(aq)}\\). The student records the following data.  | Trial | Substance added | Time to collect \\(20.0 \\text{ mL}\\) of \\(\\text{O}_2\\text{(g)}\\) | |—|—|—| | 1 | None | \\(160 \\text{ s}\\) | | 2 | \\(\\text{KI(aq)}\\), a source of \\(\\text{I}^-\\text{(aq)}\\) | \\(40 \\text{ s}\\) | | 3 | \\(\\text{MnO}_2\\text{(s)}\\) | \\(30 \\text{ s}\\) |  Additional tests show that \\(\\text{I}^-\\text{(aq)}\\) is regenerated during trial 2 and that the solid in trial 3 can be recovered unchanged. Which statement correctly classifies the two catalysts and explains the shorter collection times?"
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url: "https://nerd-notes.com/ubq/119448/"
date_modified: "2026-08-19T12:40:27+00:00"
---

# The decomposition of hydrogen peroxide is represented by the following equation.

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

A student performs three trials at the same temperature using the same initial amount and concentration of \(\text{H}_2\text{O}_2\text{(aq)}\). The student records the following data.

| Trial | Substance added | Time to collect \(20.0 \text{ mL}\) of \(\text{O}_2\text{(g)}\) |
|—|—|—|
| 1 | None | \(160 \text{ s}\) |
| 2 | \(\text{KI(aq)}\), a source of \(\text{I}^-\text{(aq)}\) | \(40 \text{ s}\) |
| 3 | \(\text{MnO}_2\text{(s)}\) | \(30 \text{ s}\) |

Additional tests show that \(\text{I}^-\text{(aq)}\) is regenerated during trial 2 and that the solid in trial 3 can be recovered unchanged. Which statement correctly classifies the two catalysts and explains the shorter collection times?

The decomposition of hydrogen peroxide is represented by the following equation.

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

A student performs three trials at the same temperature using the same initial amount and concentration of \(\text{H}_2\text{O}_2\text{(aq)}\). The student records the following data.

| Trial | Substance added | Time to collect \(20.0 \text{ mL}\) of \(\text{O}_2\text{(g)}\) |
|---|---|---|
| 1 | None | \(160 \text{ s}\) |
| 2 | \(\text{KI(aq)}\), a source of \(\text{I}^-\text{(aq)}\) | \(40 \text{ s}\) |
| 3 | \(\text{MnO}_2\text{(s)}\) | \(30 \text{ s}\) |

Additional tests show that \(\text{I}^-\text{(aq)}\) is regenerated during trial 2 and that the solid in trial 3 can be recovered unchanged. Which statement correctly classifies the two catalysts and explains the shorter collection times?

- **A.** The \(\text{I}^-\text{(aq)}\) catalyst is heterogeneous, whereas the \(\text{MnO}_2\text{(s)}\) catalyst is homogeneous; both increase the reaction rate because each provides an alternate mechanism with a lower activation energy.
- **B.** The \(\text{I}^-\text{(aq)}\) catalyst is homogeneous, whereas the \(\text{MnO}_2\text{(s)}\) catalyst is heterogeneous; both increase the reaction rate because each provides an alternate mechanism with a lower activation energy.
- **C.** The \(\text{I}^-\text{(aq)}\) catalyst is homogeneous, whereas the \(\text{MnO}_2\text{(s)}\) catalyst is heterogeneous; both increase the reaction rate because each lowers the activation energy of the original mechanism without providing an alternate pathway.
- **D.** The \(\text{I}^-\text{(aq)}\) catalyst is homogeneous, whereas the \(\text{MnO}_2\text{(s)}\) catalyst is heterogeneous; both increase the reaction rate because each increases the concentration of \(\text{H}_2\text{O}_2\text{(aq)}\), resulting in more frequent collisions.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119448/*