Final answer:
The combustion of methane to form CO2 and 2H2O is an exothermic reaction, which releases heat and is represented by CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + energy.
Step-by-step explanation:
The combustion of methane (CH4) to form CO2 and 2H2O is an example of an exothermic reaction, which means it releases heat. When methane burns in the presence of oxygen, the products carbon dioxide and water are formed, along with the release of energy. This process can typically be represented by the following equation: CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + energy. This reaction is not endothermic (heat consuming), it does not represent no change in enthalpy, and it is not an isobaric process.