CHEM 1111 Chapter 11: Chapter 11 - Gases
Document Summary
Gases that exist at room temperatures (there are only few): hydrogen, nitrogen oxygen, fluorine, chlorine, and noble gases. Noble gases exist as isolated atoms, whereas others are diatomics. Many molecular compounds exist (mostly those with low molar masses) exist as gases at room temperature. How gases differ from solids and liquids (called the condensed phases) - all these characteristics result from the properties of gases at the molecular level. A sample of gas assumes both the shape and volume of its container. The densities of gases are much smaller than those of liquids and solids; and the density of a gaseous substance is highly variable depending on temperature and pressure. Density of gases usually expressed in g/l, whereas those of liquids in solids are expressed in g/ml or g/cm^3. Hot air is less dense than cold air. Gases for homogenous mixtures (aka solutions) with one another in any proportion. Gases that don"t react with each other are mutually miscible.
