CH 304K 1st Edition Lecture 17 Outline of Last Lecture I. Photons of UV Outline of Current Lecture II. Natural Ozone DestroyersIII. CFC’s and HalonsIV. Holes at AntarcticaV. Getting Rid of CFC’sCurrent LectureNatural Ozone Destroyers- H, OH - Radicals- CFC’s and HalonsCFC’s and Halons- CFC: Chlorofluorocarbon- Have low chemical reactivity which is bad!- They are unreactive in the troposphere, but are broken down in the stratosphere by UV and create free Chlorine radicals- Chlorine radicals are a catalyst for O3 destroying reactions- Fluorine and chlorine radicals found in the stratosphere- No natural atmospheric sources of Fluorine radicals (they are all made as a result of human activity)- Only source of Fluorine radicals is from CFC’sGetting Rid of CFC’sThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- CFC’s last about 100 years in the stratosphere- CFC’s in spray cans were banned in North America in 1978, banned as foaming agents in 1990- Montreal Protocol (1987)- US and 140 other countries stopped CFC production by end of 1995- Last use was in medical inhalers; ended that in 2008- Current goal: phase out more related compounds including halons and carbon
View Full Document
Unlocking...