5 Steps to a 5 AP Chemistry

Answer: Dimethyl ether will have the higher vapor pressure and the lower boiling

point.

Explanation: Water is a polar substance with strong intermolecular hydrogen bonds.

Dimethyl ether is a polar material with weaker intermolecular forces (dipole–dipole). It will

172  Step 4. Review the Knowledge You Need to Score High

Solid

Liquid

Gas

Pressure

Temperature

Triple point

Deposition

Sublimation

Fusion

(Melting)

Freezing

Vaporization

Condensation

Critical

D Bpoint

A

C

Figure 12.4 A phase diagram.

Figure 12.5 Phase diagram for H 2 O.

Pressure (atm)

Temperature (°C)

− 1 100

Triple point

(0.01°C, 0.006 atm)

Critical point

(374°C, 218 atm)

1.0

SOLID LIQUID

GAS