SKILLCAT EPA 608 FINAL EXAM QUESTIONS AND VERIFIED ANSWERS |ALREADY
GRADED A+| 2024/2025 UPDATE
Do natural events like volcanic eruptions contribute to chlorine in the stratosphere? -
✔ANSWER Yes, but they are not the primary source.
What absorbs and reflects harmful UV rays from the sun? - ✔ANSWER Ozone, but ground
level ozone does not.
How does ozone depletion affect humans? - ✔ANSWER Increased risk of skin cancer and
cataracts.
What is fractionation of refrigerants? - ✔ANSWER It is when refrigerants settle into layers
and happens in vapor phase.
What is temperature glide? - ✔ANSWER The difference between the bubble and dew point.
What is bubble point? - ✔ANSWER The temperature at which the first refrigerant in a blend
turns to vapor.
What is the definition of dew point? - ✔ANSWER The temperature at which vapor
condenses into liquid.
What is the temperature at which the first refrigerant in a blend turns to liquid? - ✔ANSWER
The temperature at which the first refrigerant in a blend turns to liquid is not specified in
the notes.
What is a ternary blend? - ✔ANSWER A ternary blend is three refrigerants blended
together.
,What is retrofitting in the context of refrigerants? - ✔ANSWER Retrofitting involves
modifying components of the system to use a new refrigerant.
What are reasons to not mix your own refrigerants? - ✔ANSWER It is illegal, it can cause
equipment failure, and the resulting mix has unpredictable temperatures.
If a refrigerant has a drop-in replacement, is a retrofit needed? - ✔ANSWER No, if a
refrigerant has a drop-in replacement, then no retrofit is needed.
Is it true that in a zeotropic blend, all refrigerants have the same boiling point? - ✔ANSWER
False, in a zeotropic blend, not all refrigerants have the same boiling point.
Is R-407c an azeotropic blend? - ✔ANSWER False, R-407c is not an azeotropic blend.
How should refrigerant blends be charged? - ✔ANSWER Refrigerant blends need to be
charged as a liquid.
Do refrigerant blends take on the ASHRAE number of the main refrigerant in the blend? -
✔ANSWER False, refrigerant blends do not take on the ASHRAE number of the main
refrigerant.
Can technicians make their own EPA-approved refrigerant blends? - ✔ANSWER False,
technicians cannot make their own EPA-approved refrigerant blends.
Is there evidence that refrigerants are in the stratosphere? - ✔ANSWER Yes.
What is a true statement about chlorine in the atmosphere? - ✔ANSWER A single chlorine
atom can survive for years.
, How many atoms of oxygen does ozone have? - ✔ANSWER 3
Where is the majority of ozone located? - ✔ANSWER In the stratosphere, not the
troposphere.
How many molecules of ozone can three molecules of chlorine destroy? - ✔ANSWER
300,000.
What is the major function of ozone in the stratosphere? - ✔ANSWER To absorb and reflect
UV rays from the sun.
What is the primary source of chlorine in the stratosphere? - ✔ANSWER Emissions of
refrigerant chemicals like CFCs and HCFCs by humans.
What molecule is responsible for ozone layer destruction? - ✔ANSWER Chlorine.
What are the effects of ozone depletion? - ✔ANSWER Decreasing crop yields.
Which refrigerant chemicals destroy the ozone layer? - ✔ANSWER CFCs and HCFCs.
Who does ozone depletion affect? - ✔ANSWER People all over the world.
What does the Clean Air Act state about refrigerants that deplete ozone? - ✔ANSWER It is a
violation to purposely vent them.
Can technicians service equipment containing phased-out refrigerants? - ✔ANSWER Yes.
GRADED A+| 2024/2025 UPDATE
Do natural events like volcanic eruptions contribute to chlorine in the stratosphere? -
✔ANSWER Yes, but they are not the primary source.
What absorbs and reflects harmful UV rays from the sun? - ✔ANSWER Ozone, but ground
level ozone does not.
How does ozone depletion affect humans? - ✔ANSWER Increased risk of skin cancer and
cataracts.
What is fractionation of refrigerants? - ✔ANSWER It is when refrigerants settle into layers
and happens in vapor phase.
What is temperature glide? - ✔ANSWER The difference between the bubble and dew point.
What is bubble point? - ✔ANSWER The temperature at which the first refrigerant in a blend
turns to vapor.
What is the definition of dew point? - ✔ANSWER The temperature at which vapor
condenses into liquid.
What is the temperature at which the first refrigerant in a blend turns to liquid? - ✔ANSWER
The temperature at which the first refrigerant in a blend turns to liquid is not specified in
the notes.
What is a ternary blend? - ✔ANSWER A ternary blend is three refrigerants blended
together.
,What is retrofitting in the context of refrigerants? - ✔ANSWER Retrofitting involves
modifying components of the system to use a new refrigerant.
What are reasons to not mix your own refrigerants? - ✔ANSWER It is illegal, it can cause
equipment failure, and the resulting mix has unpredictable temperatures.
If a refrigerant has a drop-in replacement, is a retrofit needed? - ✔ANSWER No, if a
refrigerant has a drop-in replacement, then no retrofit is needed.
Is it true that in a zeotropic blend, all refrigerants have the same boiling point? - ✔ANSWER
False, in a zeotropic blend, not all refrigerants have the same boiling point.
Is R-407c an azeotropic blend? - ✔ANSWER False, R-407c is not an azeotropic blend.
How should refrigerant blends be charged? - ✔ANSWER Refrigerant blends need to be
charged as a liquid.
Do refrigerant blends take on the ASHRAE number of the main refrigerant in the blend? -
✔ANSWER False, refrigerant blends do not take on the ASHRAE number of the main
refrigerant.
Can technicians make their own EPA-approved refrigerant blends? - ✔ANSWER False,
technicians cannot make their own EPA-approved refrigerant blends.
Is there evidence that refrigerants are in the stratosphere? - ✔ANSWER Yes.
What is a true statement about chlorine in the atmosphere? - ✔ANSWER A single chlorine
atom can survive for years.
, How many atoms of oxygen does ozone have? - ✔ANSWER 3
Where is the majority of ozone located? - ✔ANSWER In the stratosphere, not the
troposphere.
How many molecules of ozone can three molecules of chlorine destroy? - ✔ANSWER
300,000.
What is the major function of ozone in the stratosphere? - ✔ANSWER To absorb and reflect
UV rays from the sun.
What is the primary source of chlorine in the stratosphere? - ✔ANSWER Emissions of
refrigerant chemicals like CFCs and HCFCs by humans.
What molecule is responsible for ozone layer destruction? - ✔ANSWER Chlorine.
What are the effects of ozone depletion? - ✔ANSWER Decreasing crop yields.
Which refrigerant chemicals destroy the ozone layer? - ✔ANSWER CFCs and HCFCs.
Who does ozone depletion affect? - ✔ANSWER People all over the world.
What does the Clean Air Act state about refrigerants that deplete ozone? - ✔ANSWER It is a
violation to purposely vent them.
Can technicians service equipment containing phased-out refrigerants? - ✔ANSWER Yes.
