Vapor Pressure and Boiling

The lower the boiling point, the ___ the intermolecular forces.

• stronger

• weaker

When the atmospheric pressure equals the equilibrium vapor pressure ___ occurs.

• freezing

• melting

• boiling

• sublimation

If the rate of melting equals the rate of freezing...

• there is more liquid

• there is more solid

• the system is in equilibrium

•  the system is working towards equilibrium

During a phase change, the temperature

• increases

• decreases

• fluctuates

• stays the same

The strength of intermolecular forces varies between liquids, therefore they will have

• different equilibrium vapor pressure

• the same equilibrium vapor pressure

• different temperatures

• the same amount of kinetic energy

Liquids with weak intermolecular forces

• contain a lot of kinetic energy

• easily evaporate

• cannot diffuse

• freeze easily

What is the normal boiling point of water

• 0^oC

• 100^oF

• 50^oC

• 100^oC

At which temperature is the vapor pressure of ethanol equal to 80 kPa? Use Table H.

• 48^oC

• 73^oC

• 80^oC

• 101^oC

Which compound has the lowest vapor pressure at 50°C? Use Table H.

• ethanoic acid

• ethanol

• propanone

• water

Evaporation occurs when water changes into

• ice

• liquid

• crystals

• vapor