試題詳解

13. A certain substance, X, has a triple-point temperature of 20°C at a pressure of 2.0 atm. Which one of the following statements cannot possibly be true?
(A) X can exist as a liquid above 20°C.
(B) X can exist as a solid above 20°C.
(C) Liquid X can exist as a stable phase at 25°C, 1 atm.
(D) Both liquid and solid X have the same vapor pressure at 20°C.
(E) All of these statements could be true.