Which weighs more, air or propane vapor?

The correct answer is propane vapor because it is denser than air. In general, propane gas has a molecular weight of around 44.1 g/mol, while the average molecular weight of air is approximately 28.8 g/mol. This indicates that propane vapor is significantly heavier, resulting in it having a higher density compared to air.

Understanding the density of gases is essential in various practical applications, such as safety measures in environments where propane is used or stored. Propane vapor being heavier than air means that if there is a gas leak, the propane will tend to accumulate at lower levels. This is why proper ventilation and monitoring are crucial in areas where propane is present.

While liquid propane is heavier than propane vapor due to its state, the question specifically asks about the vapor form, clarifying that only the weights of gases are under consideration. Thus, the distinction in molecular weights clearly supports that propane vapor weighs more than air.