1. Identify the phase in which the water molecules are closest together.

A) gas

B) dry ice

C)

solid

D) liquid

2. Determine the phases of matter for the following points on the phase diagram of CO₂.

Pressure (not to scale)

72.9.

atm

5.1

atm

1 atm

Triple

SOLID point

LIQUID

a. 20.0 °C, 72.9 atm

b. -56.7 °C, 5.1 atm

c. 10.0 °C, 1.0 atm

d. -78.5 °C, 1.0 atm

e. 50.0 °C, 80.0 atm

GAS

-78.5°C -56.7 °C

Temperature (not to scale)

Carbon dioxide

Intermolecular forces

31 °C

Critical

point