R-407C is an azeotropic blend.

R-407C is an azeotropic blend.

• A. True
• B. It depends on temperature
• C. False
• D. Only at high pressures

Answer: (C)

R-407C is not an azeotropic blend. An azeotrope boils at a single, constant temperature with the liquid and vapor having the same composition at a given pressure. R-407C, a mixture of R-32, R-125, and R-134a, behaves as a zeotrope: as it boils, the vapor is richer in the more volatile component and the liquid left behind changes in composition, causing a temperature glide during phase change. This nonzero glide means it does not maintain a constant boiling point, so it is not truly azeotropic (though it’s sometimes described as near-azeotropic). Therefore, the statement is false.

R-407C is not an azeotropic blend. An azeotrope boils at a single, constant temperature with the liquid and vapor having the same composition at a given pressure. R-407C, a mixture of R-32, R-125, and R-134a, behaves as a zeotrope: as it boils, the vapor is richer in the more volatile component and the liquid left behind changes in composition, causing a temperature glide during phase change. This nonzero glide means it does not maintain a constant boiling point, so it is not truly azeotropic (though it’s sometimes described as near-azeotropic). Therefore, the statement is false.