Section: Chemistry: Section I

13) At STP, which gas has properties most similar to those of an ideal gas?

1. NH₃
2. CO₂
3. O₂
4. H₂

An ideal gas has two key characteristics:

1) Its molecules are small, so that the total volume of the molecules themselves is negligible when compared to the volume of the container in which they are kept.

2) There are no electrical bonds with neighboring molecules.

Of the choices given, H₂comes the closest to these features of an ideal gas.