Chapter 6 Introduction to Refrigerants
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19. How can the refrigerant temperature in an air-
cooled condenser be determined?
A. By adding 30°F to 35°F to the ambient
temperature around the condenser
B. By subtracting 25°F from the present
condenser temperature
C. By placing a probe inside the suction line
D. None of the above.
20. The azeotropic blend R-508B is made of which
two refrigerants?
A. R-22 and R-124
B. R-143a and R-134a
C. R-32 and R-125
D. R-116 and R-23
21. In 2010, the United States stopped
manufacturing new units that contain _____ ,
a widely used HCFC refrigerant.
A. R-12
B. R-22
C. R-134a
D. R-410A
22. Which of the following is not a desirable
property for new refrigerants?
A. Noncorrosive
B. Nonexplosive
C. High boiling point
D. Stable gas
23. Which of the following refrigerants has a low
GWP and can be used as a replacement for
R-134a in automotive air conditioning?
A. R-125
B. R-717
C. R-410A
D. R-1234yf
24. The colorless refrigerant often used in
absorption systems that has a distinct odor
is _____.
A. R-704
B. R-717
C. R-728
D. R-744
25. A fl oc test determines the temperature at which
_____ separates out of a mixture of refrigerant
and lubricant.
A. water
B. mineral oil
C. wax
D. polyol ester
26. Which term is a measure of a liquid’s resistance
to fl ow?
A. Viscosity
B. Floc point
C. Flash point
D. Chemical stability
27. Which type of lubricant is not miscible with
HFC refrigerants?
A. Alkylbenzene
B. Polyol ester
C. Mineral oil
D. Polyalkylene