Can the process of rusting be called combustion? Discuss.

Let's look at the similarities and differences between rusting and combustion that will help us to deduce if rusting can be called combustion:

Similarities between rusting and combustion:

1. Both involve oxygen — Both processes require oxygen from the air. In combustion, oxygen reacts with the fuel, and in rusting, it reacts with the metal (often iron).
2. Both are exothermic — Both processes release energy in the form of heat. However, the amount of heat released is significantly different. Combustion releases a much larger amount of heat, often accompanied by light. Rusting releases a minimal amount of heat that's usually undetectable.

Differences between rusting and combustion:

1. Rate of reaction — Combustion is a rapid process, often instantaneous or occurring within seconds. Rusting is a slow, continuous process that can take hours, days, or even years depending on the conditions.
2. Ignition temperature — For combustion to take place, the fuel should attain its Ignition temperature. Rusting does not require an ignition temperature and can occur at room temperature.
3. Products — Combustion typically produces water vapour, carbon dioxide, and other gases as products. Rusting produces iron oxide, commonly known as rust.

Therefore, while both involve oxygen and release heat, the significant differences in reaction rate, ignition temperature and products formed prevent us from calling rusting as combustion.