Final answer:
d) 100% During the combustion process of fuel-oil, ideally, 100% of the carbon content combines with oxygen to form carbon dioxide and carbon monoxide,
Step-by-step explanation:
When considering the combustion process of fuel-oil, essentially 100% of the carbon content should combine with oxygen to form carbon dioxide (CO₂) and carbon monoxide (CO), given a sufficient supply of oxygen. However, when the oxygen supply is limited, carbon monoxide is more likely to form over carbon dioxide due to incomplete combustion.
The formation of carbon monoxide can be represented by the reaction: 2 C(s) + O₂(g) → 2 CO(g). Furthermore, carbon monoxide can react with more oxygen to form carbon dioxide, shown in the reaction: CO(g) + 1/2 O₂(g) → CO₂(g). These chemical equations illustrate that, ideally, all carbon in the fuel should react with oxygen.
The presence of carbon monoxide as a by-product of combustion, especially in poorly ventilated or improperly adjusted heaters, can be dangerous, leading to health risks. Therefore, it is crucial to ensure adequate air supply to achieve complete combustion and minimize the formation of carbon monoxide.