To determine whether the combustion of methane is endothermic or exothermic, let's closely examine the given chemical equation:
[tex]\[
CH_4(g) + 2O_2(g) \rightarrow CO_2(g) + 2H_2O(g) + \text{energy}
\][/tex]
1. Understanding the Chemical Reaction:
- Reactants: Methane (CH[tex]\(_4\)[/tex]) and Oxygen (O[tex]\(_2\)[/tex]).
- Products: Carbon Dioxide (CO[tex]\(_2\)[/tex]), Water (H[tex]\(_2\)[/tex]O), and Energy.
2. Energy Consideration:
In any chemical reaction, the energy involving the breaking and forming of chemical bonds is crucial to determine if a reaction is endothermic or exothermic.
- Endothermic Reaction: This type of reaction absorbs energy from the surroundings, resulting in a net intake of energy. Such reactions feel cold to the touch as they require energy.
- Exothermic Reaction: This type of reaction releases energy to the surroundings, resulting in a net release of energy. Such reactions usually feel warm or hot to the touch as they release energy.
3. Given Information:
The chemical equation explicitly states that energy is produced as a product of the reaction. The inclusion of energy on the right side of the equation indicates that the reaction releases energy.
4. Conclusion:
Since the reaction produces energy and releases it into the surroundings, this indicates the reaction is exothermic.
Thus, the combustion of methane is an exothermic reaction.
[tex]\[
\boxed{\text{exothermic}}
\][/tex]
