What belongs in the blank space following chemical equation for the dunning of fossil fuels?

To provide a specific answer, I would need the actual chemical equation you're referring to, as the burning of fossil fuels can represent different reactions depending on the type of fuel. Generally, the combustion of fossil fuels like coal, oil, or natural gas typically involves a hydrocarbon reacting with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O). If you can provide the specific equation or context, I can give a more precise answer.