CHEM 112 Lecture Notes - Lecture 11: Emission Spectrum, Ideal Gas, Partial Pressure

• School: Queen's University
• Department: Chemistry
• Course: CHEM 112
• Professor: Richard Oleschuk

Document Summary

Earth"s atmosphere is mostly pressures well below 100kpa sp the overall behaviour is close to ideal. Global atmosphere models routinely depend on ideal gas laws. Atmosphere is divided into layers based on temperature trends. Big idea: why do layers where t decreases with altitude (troposphere) are more homogenous than layers where t increases with altitude (stratosphere) Atmosphere is over 99% nitrogen and oxygen, everything else is trace except for water. Water is highly variable, from 5% to trace depending on time and place. Note ppmv units which is the same as partial volume . In 1l a 400 ppm gas occupies 1l(400 x 10^-4)=0. 4ml. Recall partial volume= partial pressure: air at 100 kpa, 400 ppm, gas has a partial pressure of 100 kpa x 400x10^- Methane is 23 times more potent than co2 as a greenhouse gas (each molecule traps more heat in atmosphere)