Critical temperature comparison Evaluate the statement: “Among common legacy refrigerants, R-11 has one of the highest critical temperatures.”

Introduction / Context:
The critical temperature of a refrigerant strongly influences condenser design and achievable cycle performance in warm climates. Higher critical temperatures generally make condensation easier at high ambient conditions.

Given Data / Assumptions:

• Comparison among common legacy single-component refrigerants like R-11, R-12, R-22, etc.
• No detailed numerical values are required; qualitative ranking is sufficient.

Concept / Approach:
R-11 (trichlorofluoromethane) has a notably high critical temperature compared with many other legacy refrigerants (e.g., R-12, R-22). This historically favored its use in large centrifugal chillers for comfort cooling, where high condensing temperatures can occur.

Step-by-Step Solution:
Recognize R-11’s property set: low pressures, high molecular weight, and high critical temperature.Relate to application: easier condensation in warm climates makes chiller design more forgiving.Therefore, the qualitative statement is correct.

Verification / Alternative check:
Property tables show R-11 critical temperature significantly higher than R-12 and R-22, aligning with historical use cases.

Why Other Options Are Wrong:
Options adding conditions (c), (d), (e) are irrelevant to the intrinsic property. Saying “Incorrect” ignores well-documented data.

Common Pitfalls:
Conflating critical temperature with normal boiling point; both influence design, but the critical value is the upper limit for condensation.

Final Answer:
Correct