CHE 106 Lecture Notes - Lecture 23: Molecular Mass, Root Mean Square, Effusion

• School: Syracuse University
• Department: Chemistry
• Course: CHE 106
• Professor: J.French

Document Summary

The law of partial pressures and mole fractions are concepts used to deal with gas mixtures. Dalton"s law of partial pressures : the sum of the pressures of all diff gases in the mixture must equal our total pressure. The composition of a gas mixture is often described in terms of its mole fraction. Mole fraction (x) : the fraction of a mole of that gas from the total moles. A useful application of partial pressures arises when you collect gases over water. We want to measure the h2 pressure, but water vapor interferes. As gas bubbles through the water, the gas becomes saturated with water vapor. The partial pressure of the water in this mixture depends only on the temperature. Kinetic molecular theory : pressure is caused by the molecules in constant collision of the gas molecules with the boundaries of their container.