What type of reaction is shown below? Check all that apply. 2H2O2 → 2H2O + O2
The Correct Answer and Explanation is:
The reaction 2H2O2 → 2H2O + O2 is a decomposition reaction and it can also be considered a redox reaction. Let’s break it down:
1. Decomposition Reaction:
In a decomposition reaction, a single reactant breaks down into two or more products. Here, hydrogen peroxide (H2O2) is decomposing into water (H2O) and oxygen (O2). This fits the definition of a decomposition reaction.
- Reactant: 2H2O2 (hydrogen peroxide)
- Products: 2H2O (water) and O2 (oxygen)
2. Redox (Reduction-Oxidation) Reaction:
In redox reactions, one substance undergoes oxidation (losing electrons) and another undergoes reduction (gaining electrons). In this case, hydrogen peroxide (H2O2) is both oxidized and reduced.
- Oxidation: The oxygen in H2O2 is oxidized. In hydrogen peroxide (H2O2), the oxygen is in the -1 oxidation state. As H2O2 decomposes to produce O2, the oxidation state of oxygen changes to 0 in O2, meaning it has been oxidized.
- Reduction: The hydrogen in H2O2 remains in the +1 oxidation state in both the reactant (H2O2) and product (H2O). Thus, the oxygen in H2O2 gets reduced as it forms water (H2O) where it is in the -2 oxidation state.
3. Exothermic Reaction:
This reaction is also exothermic. The breakdown of hydrogen peroxide releases energy in the form of heat. This energy release makes the reaction spontaneous under certain conditions.
4. Catalytic Reaction (optional context):
In some cases, the decomposition of hydrogen peroxide is catalyzed by substances like potassium iodide (KI) or manganese dioxide (MnO2). However, this is not a requirement for the reaction to occur, so while it could be catalytic in nature, it is not inherently catalytic without the presence of a catalyst.
Conclusion:
To summarize:
- Decomposition Reaction: Because H2O2 breaks down into two products.
- Redox Reaction: Due to the oxidation and reduction of oxygen atoms.
- Exothermic: The reaction releases heat.
