G2 Gas Fitter Practice Exam

Which gases are considered inert in the context of combustion?

1. Carbon dioxide and nitrogen

2. Oxygen and carbon dioxide

3. Nitrogen and hydrogen

4. Helium and ozone

The correct answer is: Carbon dioxide and nitrogen

In the context of combustion, inert gases are those that do not readily react with other substances, particularly during the combustion process. In this scenario, carbon dioxide and nitrogen are recognized for their inertness in combustion. Carbon dioxide is a product of combustion rather than a reactant, meaning it does not support combustion or contribute to the burning process. It exists in a state where it cannot create flames, but rather serves to suppress combustion when present in significant concentrations. Nitrogen, which makes up a large portion of the Earth's atmosphere, is also considered inert in combustion processes. It does not readily react with other compounds and acts as a diluent in combustion reactions, effectively limiting the amount of oxygen available for combustion. This characteristic means that nitrogen does not participate in burning and remains unchanged in combustion environments. Together, carbon dioxide and nitrogen effectively serve as inert gases, highlighting their roles in combustion dynamics. The other options include gases that either actively participate in combustion or are not typically categorized as inert in this context.