Final answer:
The products of the complete combustion of methane (CH₄) in plentiful air are carbon dioxide (CO₂) and water (H₂O), along with released energy in the form of heat.
Step-by-step explanation:
When CH₄ (methane) is burned in plentiful air, the products are carbon dioxide (CO₂) and water (H₂O). The complete combustion reaction of methane with oxygen is represented by the chemical equation:
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)
This reaction also releases a substantial amount of energy in the form of heat. The correct answer to the question is therefore option 4) CO₂ + H₂O.
When there is a limited supply of oxygen, incomplete combustion may occur, potentially forming products like carbon monoxide (CO) and elemental carbon (C), along with water. However, under plentiful air conditions, complete combustion is expected, leading to the formation of CO₂ and H₂O as the primary products.