Question 1

At point A on the phase diagram, what is the physical state of the substance?

Accepted Answer

Gas

Question 2

What does point B on the phase diagram represent?

Accepted Answer

The triple point

Question 3

If the substance is at 120°C and 760 mm Hg, what is its physical state?

Accepted Answer

Liquid

Question 4

What phase change occurs when moving from point C to point A at constant pressure?

Accepted Answer

Vaporization

Question 5

At what temperature and pressure does the triple point occur in this diagram?

Accepted Answer

$$t = 20^\circ C$$, $$P = 35 mm Hg$$

Question 6

What is the significance of point A on the phase diagram?

Accepted Answer

It is the critical point.

Question 7

If the substance is at 5°C and 1 atm, what is its physical state?

Accepted Answer

Solid

Question 8

If a sample is at 100°C and 800 mm Hg and the temperature is decreased to 5°C at constant pressure, which phase change will occur?

Accepted Answer

Freeze

Question 9

Which letter on the diagram represents the critical point?

Accepted Answer

A

Question 10

Which of the following best describes the region to the left of point B at low temperature and pressure?

Accepted Answer

Solid phase

Phase Diagram Interpretation and Thermochemistry

Study Guide - Practice Questions