L1 /
7
CH3041
CFC’s I
• ChloroFluoroCarbons (CFCs) or Freons
• Methyl chloride, methyl bromide CH3X
- major natural halocarbons. X= Cl, Br
- major natural halocarbons. X= Cl, Br
• CFCl3 CFC-11; CF2Cl2 CFC-12 (Dupont, 1930s)
• “Rule of 90”
= add 90 to the code no, the
new no gives C:H:F the rest are Cl
new no gives C:H:F the rest are Cl
eg. CFC-12 Þ 90
+ 12 Þ 102 Þ C1F2Cl2
• Refrigerants
- replaced toxic SO2 and NH3
- Compress to a
liquid, BP a little below RT
- Non-toxic,
non-flammable ... great!
• Completely unreactive in the
troposphere
