Why do saturated hydrocarbons generally produce a clean flame, and what happens when the air supply is limited?

Saturated hydrocarbons generally produce a clean flame because they undergo complete combustion when exposed to an adequate air supply. In complete combustion, the hydrocarbon reacts with oxygen to form carbon dioxide and water vapor, releasing energy. However, when the air supply is limited, incomplete combustion occurs. In such cases, saturated hydrocarbons may produce a sooty flame due to the formation of carbon particles or carbon monoxide instead of complete combustion by-products. The limited supply of oxygen prevents the hydrocarbon from fully reacting, leading to the production of less desirable and potentially harmful combustion products.