Question

The critical point of CCl4 is 283°C and 45 atm pressure. Liquid CCl4 has a vapor pressure of 10.0 atm at 178°C. Which of the following statements must be true?

(a) the normal boiling point of CCl4 must be greater than 178°C
(b) liquid CCl4 can exist at temperatures greater than 283°C if the pressure is greater than 45 atm
(c) the triple point of CCl4 must be less than 178°C
(d) liquid and solid can only be in equilibrium at one temperature—the freezing point
(e) vapor and liquid can only be in equilibrium at one temperature—the normal boiling point