CFC Chlorofluorocarbon Properties & Environmental Impact 4

Question 1

What UV radiation wavelength range (nm) is most effectively absorbed by stratospheric ozone, protecting life on Earth?

Accepted Answer

UV-B: 280–315 nm

Answer

Stratospheric ozone primarily absorbs UV-B radiation (280–315 nm), which is the range most damaging to DNA, skin cells, and marine ecosystems.

Question 2

The Halogen numbering system for refrigerants: what does the digit in the 'tens' place of a three-digit refrigerant number indicate?

Accepted Answer

Number of carbon atoms minus one

Answer

In the ASHRAE refrigerant numbering system, the tens digit equals the number of carbon atoms minus one; for single-carbon molecules (methane-based), this digit is 0.

Question 3

Which greenhouse gas metric compares the warming impact of a CFC relative to CO₂ over a 100-year period?

Accepted Answer

Global Warming Potential (GWP)

Answer

Global Warming Potential (GWP) quantifies how much heat a greenhouse gas traps over 100 years relative to CO₂, which is assigned a GWP of 1.

Question 4

R-114 (CFC-114) was commonly used in which specific application before its phase-out?

Accepted Answer

Centrifugal chillers for large building cooling

Answer

R-114 (dichlorotetrafluoroethane) was used in centrifugal chillers for large commercial and industrial cooling applications due to its low pressure operating characteristics.

Question 5

What is the primary reason CFC molecules are so stable in the lower atmosphere (troposphere)?

Accepted Answer

They lack C-H bonds and are resistant to hydroxyl radical attack

Answer

CFCs lack hydrogen atoms, so the hydroxyl (OH) radical—which breaks down most organic compounds in the troposphere—cannot attack them, allowing CFCs to persist and migrate to the stratosphere.

(CFC) Chlorofluorocarbon Certification Practice Test

(CFC) Chlorofluorocarbon Certification Practice Test

CFC Chlorofluorocarbon Properties & Environmental Impact 4