PB1.Q9.ii

At what temperature does the substance represented in the cooling curve condense?

• 150°C

• 60°C

• 10°C

• 0°C

During condensation, what happens to the temperature of the substance?

• It increases.

• It decreases.

• It remains constant.

• It fluctuates.

What does the horizontal portion of the cooling curve at 60°C represent?

• The substance is cooling down as a liquid.

• The substance is undergoing a phase change from gas to liquid.

• The substance is undergoing a phase change from liquid to solid.

• The substance is heating up as a gas.

In what temperature range is the substance in a liquid state?

• Above 150°C

• Between 60°C and 10°C

• Below 10°C

• Between 150°C and 60°C, and between 10°C and 0°C.

What is happening to the substance between 150°C and 60°C on the cooling curve?

• It is changing from a gas to a liquid.

• It is changing from a liquid to a solid.

• It is cooling down as a gas.

• It is cooling down as a liquid.

What is the melting point of the substance, according to the cooling curve?

• 150°C

• 60°C

• 10°C

• 0°C

Why is ice at 0°C more effective at cooling a drink than ice-cold water at 0°C?

• Ice has a lower specific heat capacity than water.

• Ice absorbs heat to melt (latent heat of fusion) in addition to absorbing heat to raise its temperature.

• Ice has a higher density than water.

• Ice is colder than ice-cold water.

What is the specific latent heat?

• The amount of heat required to change the temperature of 1 kg of a substance by 1°C.

• The amount of heat required to change the state of 1 kg of a substance without a change in temperature.

• The amount of heat required to raise the temperature of a substance from its freezing point to its boiling point.

• The amount of heat required to cool a substance from its boiling point to its freezing point.

What does the horizontal portion of the cooling curve at 10°C represent?

• The substance is cooling down as a liquid.

• The substance is undergoing a phase change from gas to liquid.

• The substance is undergoing a phase change from liquid to solid.

• The substance is heating up as a gas.