Certified Fire Investigator Practice Exam

What does a vapor density of .96 indicate about carbon monoxide?

1. It is heavier than air

2. It is lighter than air

3. It ignites easily

4. It has a high flash point

The correct answer is: It is lighter than air

A vapor density of 0.96 indicates that carbon monoxide is lighter than air because vapor density is a comparison of a substance's density to that of air, which has a standard vapor density of 1. A vapor density less than 1 means that the substance will rise in air since it is less dense, while a vapor density greater than 1 means it would sink. Understanding this concept is crucial when assessing the behavior of gases, especially in fire investigation contexts, where the movement of gases can influence fire spread and safety measures. In this case, knowing that carbon monoxide is lighter than air helps investigators understand its potential to accumulate in upper areas of spaces and the importance of proper ventilation and monitoring in situations where it may be present.