Answer:
supercritical fluid, 0.071, solid, liquid, gas.
The sample is initially a solid.
The final state of the substance is a solid.
No phase change will occur.
Explanation:
Let's refer to the attached phase diagram for H₂ (not to scale).
At temperatures above 33.2 K and pressures above 12.8 atm, H₂ is a supercritical fluid.
H₂ does not exist as a liquid at pressures below 0.071 atm.
H₂ is a solid at 4.84 atm and 0.2 K.
H₂ is a liquid at 1.00 atm and 15.6 K.
H₂ is a gas at 7.10×10-2 atm and 34.4 K.
I think the missing question is this:
A sample of hydrogen is initially at a pressure of 19.1 atm and a temperature of 0.6 K. The pressure on the sample is reduced to 7.10×10⁻² atm at a constant temperature of 0.6 K. Which of the following are true?
Choose all that apply
The final state of the substance is a gas. NO. At 7.10×10⁻² atm and 0.6 K, hydrogen is a solid.
The sample is initially a solid.
YES.
The gas initially present will solidify.
NO. Initially, it is solid.
The final state of the substance is a solid. YES.
No phase change will occur. YES.
