To determine the type of reaction that the given chemical equation represents, we need to understand a few key concepts about different types of chemical reactions. The chemical equation provided is:
[tex]\[
CH_4 + 2 O_2 \rightarrow CO_2 + 2 H_2O + \text{energy}
\][/tex]
### Step-by-Step Analysis:
1. Identify the reactants and products:
- Reactants: Methane ([tex]\(CH_4\)[/tex]) and Oxygen ([tex]\(O_2\)[/tex])
- Products: Carbon Dioxide ([tex]\(CO_2\)[/tex]), Water ([tex]\(H_2O\)[/tex]), and Energy.
2. Observe if energy is released or absorbed:
- The equation shows that energy is produced and appears on the product side. This means that the reaction releases energy.
3. Classify the reaction based on energy changes:
- Exothermic Reactions: These reactions release energy in the form of heat.
- Endothermic Reactions: These reactions absorb energy.
Since energy is released in this reaction (as indicated by "[tex]\(\text{energy}\)[/tex]" on the product side), the reaction is exothermic.
### Review the provided answer choices:
- A. Decomposition Reaction: This involves breaking down a single compound into two or more simpler substances. Example: [tex]\(AB \rightarrow A + B\)[/tex]. The given reaction does not fit this description as methane is combined with oxygen.
- B. Endothermic Reaction: This involves the absorption of energy from the surroundings. Energy would appear on the reactants side. The given reaction shows energy being released, not absorbed.
- C. Exothermic Reaction: This involves the release of energy, often in the form of heat. Energy appears on the products side. This matches the given reaction.
- D. Synthesis Reaction: This involves combining two or more reactants to form a single product. Example: [tex]\(A + B \rightarrow AB\)[/tex]. The given reaction involves multiple products.
### Conclusion:
Based on the analysis and the definitions of the types of reactions, the correct answer is:
C. exothermic
