Question

The substance argon has the following properties: normal melting point: 83.9 K normal boiling point: 87.4 K triple point: 0.68 atm, 83.8 K critical point: 48 atm, 150.6 K A sample of argon is initially at a pressure of 49.6 atm and a temperature of 101.4 K. The pressure on the sample is reduced to 0.680 atm at a constant temperature of 101.4 K. Which of the following are true? Choose all that apply The final state of the substance is a gas. The gas initially present will solidify. The final state of the substance is a solid. The sample is initially a liquid. One or more phase changes will occur.

Answer 1

The final state of the substance is a gas.

The sample is initially a liquid. One or more phase changes will occur.

Step-by-step explanation:

Let's consider the phase diagram for Argon (not to scale).

A sample of argon is initially at a pressure of 49.6 atm and a temperature of 101.4 K. The pressure on the sample is reduced to 0.680 atm at a constant temperature of 101.4 K. Which of the following are true? Choose all that apply

The final state of the substance is a gas. TRUE. At 0.680 atm and 101.4 K, the substance is a gas.

The gas initially present will solidify. FALSE. Initially, Ar is present as a liquid.

The final state of the substance is a solid. FALSE.

The sample is initially a liquid. One or more phase changes will occur. TRUE. The sample is initially liquid and only one phase change will occur.