a sample of hydrogen

Question

The substance hydrogen has the following properties:
normal melting point:
14.0 K
normal boiling point:
20.3 K
triple point:
7.1×10-2 atm, 13.9 K
critical point:
12.8 atm, 33.2 K

A sample of hydrogen at a pressure of 1.00 atm and a temperature of 63.4 K is cooled at constant pressure to a temperature of 15.8 K. Which of the following are true?

Choose all that apply One or more phase changes will occur.
The final state of the substance is a solid.
The sample is initially a gas.
The liquid initially present will vaporize.
The final state of the substance is a liquid.

Answer 1

The sample is initially a gas

The starting temperature is above the boiling point and the pressure is standard @ 1 atm.

 

The final state of the substance will be a liquid.

Since the pressure has been kept a 1 atm and the temperature is above the melting point but below the boiling point.