Which statement about fractionation of refrigerants is true?

• A. Is when refrigerants settle into layers
• B. Happens in vapor phase
• C. Happens in liquid phase
• D. Happens in solid phase

Answer: (A)

Fractionation is the separation of a refrigerant blend into different components because each component has a different boiling point. When a zeotropic mixture boils, the more volatile component tends to go into the vapor, while the less volatile component stays in the liquid. If the system allows these different compositions to separate, you can observe distinct layers or regions with different compositions. That layering is the observable result of fractionation, which is why describing it as refrigerants settling into layers is the best answer. It's not limited to just the vapor phase or just the liquid phase, and it doesn't involve solid phase.