1. Coal Combustion: Coal, mainly composed of carbon, is burned in a boiler with high-pressure air. This combustion process releases a significant amount of heat energy.

2. Formation of Carbon Dioxide: During combustion, the carbon atoms in coal react with oxygen (O2) from the air to produce carbon dioxide (CO2). This reaction can be represented as:

C (coal) + O2 (air) → CO2 (carbon dioxide) + heat energy

Gas station:

1. Fuel Combustion: Gasoline, composed primarily of hydrocarbons, is combusted in the engines of vehicles at gas stations. This combustion process also requires oxygen (O2) from the air.

2. Formation of Carbon Dioxide: Similar to coal combustion, the carbon atoms in gasoline react with oxygen during combustion, releasing carbon dioxide (CO2). The chemical reaction for this process is the same as in the coal-fuelled power station:

C (hydrocarbons in gasoline) + O2 (air) → CO2 (carbon dioxide) + heat energy

In summary, the formation of CO2 in both a coal-fuelled power station and a gas station occurs as a result of the combustion of carbon-based fuels with oxygen. This process is fundamental to the operation of these facilities and the generation of power or movement of vehicles, but it also contributes to the release of greenhouse gases into the atmosphere.