試題詳解

29. A certain substance, X, has a triple-point temperature of 20℃ 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℃  
(B) both liquid and solid X have the same vapor pressure at 20℃ 
(C) liquid X can exist as a stable phase at 25℃ , 1 atm
(D) X can exist as a solid above 20℃  
(E) all of these statements could be true