Chemistry 1302A/B Study Guide - Quiz Guide: Ultraviolet, Global Cooling, Smog

• School: Western University
• Department: Chemistry
• Course: Chemistry 1302A/B
• Professor: Christina Booker

Document Summary

Ozone stratospheric depletion less efficient filtration of harmful solar uv rays. Depletion by: 1) natural (water vapour, nitric oxide) & 2) human-made (chlorofluorocarbons, halons) sources. These manufactured chemicals, containing chlorine and/or bromine are called. "ozone-depleting substances" (ods). popularity of these chemicals due to their stability and low toxicity. Chloroflurocarbons (cfcs) and halons have been used as: foam-blowing agents, fire-extinguishing agents, solvents, refrigerants. However, their stability and long lifetime (up to several centuries) allows them to reach the stratosphere. molecules + uv light in the stratosphere generation of chlorine and bromine destroy stratospheric ozone. In north america, the use of chlorofluorocarbons (as propellants in spray cans) was banned in 1978 in response to the threat of ozone depletion. The global response to the threat of ozone depletion came with the signing of the montreal protocol (in 1987). It set out to reduce and ultimately ban the manufacture and use of cfcs and other ozone depleting substances.