What characteristics of CFCs make them more likely than most other chlorine compounds to reach the stratosphere?
CFCs neither dissolve in water nor break down into compounds that dissolve in water, so they do not rain out of the atmosphere
.
What is the evidence that HCFCs are in the stratosphere?
What is the strongest evidence that CFCs are in the stratosphere?
Measurements of CFCs in air samples from the stratosphere
. What compounds have the highest ozone depletion potential? May be fined.
What characteristics make it easy for CFCs to reach the stratosphere?
Gases such as CFCs that do not dissolve in water and
that are relatively unreactive in the lower atmosphere are mixed relatively quickly
and therefore reach the stratosphere regardless of their weight.
What is the strongest evidence that HCFCs or in the stratosphere?
| R-134 a refrigerant charged systems should be leak checked with: Pressurized nitrogen | What is the strongest evidence that CFC’s are in the stratosphere? Measurement of CFC’s in air samples from the stratosphere |
|---|
What do CFCs HCFCs and HFCs have in common?
CFC molecules contain chlorine atoms, and each atom can destroy thousands of ozone molecules. … While HFCs are only weak ozone-depleting substances, they are, like CFCs and HCFCs,
strong greenhouse gases
.
How many years do CFCs take to reach the stratosphere?
In fact, it can take a CFC molecule
about 2 years
after being released at the ground to make it to the stratosphere where the ozone is. And it can take decades for it to be converted by sunlight into a form that is harmful to ozone, according to Dr. Charles Jackman, an atmospheric modeler at GSFC.
Why are CFCs bad?
Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons
destroy the earth’s protective ozone layer
, which shields the earth from harmful ultraviolet (UV-B) rays generated from the sun. CFCs and HCFCs also warm the lower atmosphere of the earth, changing global climate.
What does HCFC stand for?
| Acronym Definition | HCFC Hydrochlorofluorocarbon | HCFC Harris County Flood Control District (est. 1937; Texas) | HCFC Hull City Football Club (the Sleeping Giant) | HCFC House of Commons Finance Committee (Canada) |
|---|
What replaced CFCs?
Two of the chemical classes under consideration for replacing CFCs are
hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs)
. HCFCs contribute to the destruction of stratospheric ozone, but to a much lesser extent than CFCs.
What is the strongest evidence that HCFC are in the atmosphere?
Most of the volcanic chlorine stays on ground level. Air samples taken in the stratosphere provide the strongest evidence that it is
refrigerant chemicals that are destroying the ozone
. Air samples of the stratosphere contain significantly increased amounts of CFCs and HCFCs, as well as carbon monoxide.
Which refrigerants must be recovered before opening?
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs)
have which of the following in common? They must be recovered before opening or disposing of appliances. After 1995, supplies of CFC refrigerant for equipment servicing will come from; recovery and recycling.
Which of the following is true if a system will not hold a vacuum after it has been evacuated?
Which of the following is TRUE if a system WILL NOT hold a vacuum after it has been evacuated?
The system is ready to be charged.
What type of refrigerant has the lowest global warming potential?
The refrigerant with the lowest GWP (Global Warming Potential) is
R-717
.
Are CFCs still used?
Production of
CFCs ceased in 1995
. HCFC production will cease in 2020 (HCFC-22) or 2030 (HCFC-123). This means that although equipment that uses these refrigerants may operate just fine for 20 or 30 years, new or recycled refrigerant to service it may not be available. Don’t buy equipment that uses CFC refrigerants.
How do we destroy the ozone layer?
Ozone Depletion.
When chlorine and bromine atoms come into contact with ozone in the stratosphere
, they destroy ozone molecules. One chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere. Ozone can be destroyed more quickly than it is naturally created.
What is a reason to heat a system during dehydration?
What purpose is served by heating a system during dehydration?
To speed up moisture removal
.
