CFC Chlorofluorocarbon Properties & Environmental Impact 2

Question 1

Which property of CFCs makes them particularly effective as refrigerants compared to earlier alternatives like ammonia?

Accepted Answer

Low toxicity and non-flammability

Answer

CFCs were adopted largely because they are non-toxic and non-flammable, making them safer than ammonia or sulfur dioxide in residential and commercial applications.

Question 2

The Ozone Depletion Potential (ODP) of CFC-11 (R-11) is assigned a reference value of:

Accepted Answer

1.0

Answer

CFC-11 (trichlorofluoromethane) is used as the ODP reference standard with a value of 1.0, against which all other substances are measured.

Question 3

At what altitude does the stratospheric ozone layer primarily reside that CFCs are known to deplete?

Accepted Answer

15–35 km

Answer

The stratospheric ozone layer is concentrated between approximately 15 and 35 kilometers altitude, where UV radiation converts CFC-released chlorine into ozone-destroying radicals.

Question 4

Which chemical reaction describes how a single chlorine atom released from a CFC can destroy thousands of ozone molecules?

Accepted Answer

Catalytic chain reaction

Answer

Chlorine acts as a catalyst in a chain reaction: Cl + O₃ → ClO + O₂, then ClO + O → Cl + O₂, regenerating Cl to destroy more ozone without being consumed.

Question 5

R-502, a common commercial refrigerant blend, is an azeotrope of R-22 and which other refrigerant?

Accepted Answer

R-115

Answer

R-502 is an azeotropic blend of 48.8% R-22 (HCFC) and 51.2% R-115 (CFC), widely used in low-temperature commercial refrigeration before its phase-out.

(CFC) Chlorofluorocarbon Certification Practice Test

(CFC) Chlorofluorocarbon Certification Practice Test

CFC Chlorofluorocarbon Properties & Environmental Impact 2