In the phase diagram for substance X, what is the triple point of substance X?
A) 0°C, 0 atm
B) 22°C, 4 atm
C) 29°C, 2.2 atm
D) 60°C, 5 atm

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3