Heating and Cooling Curves

​U01.L03 :
Heating and Cooling Curves

​It shows how state of matter changes with temperature.

The positive slope means thermal energy is being added.

​

​

​

​Heating

Curve

​How to Read

• During a phase change, the temperature does NOT change until every particle has switched phases.

• Energy is being removed or added, but temperature does not change during the phase change.

• Temperature changing is demonstrated with the sloped lines.

• Phase changing is demonstrated with the flat lines.​

Multiple Choice

What label is given to the first flat line on the graph?

• temperature

• boiling point

• melting point

• time

Multiple Choice

At the first flat line on the graph, what state of matter should we see?

• mix of solid and liquid

• mix of liquid and gas

• mix of solid and gas

• solid

Multiple Choice

What label is given to the second flat line on the graph?

• temperature

• boiling point

• melting point

• time

Multiple Choice

At the second flat line on the graph, what state of matter should we see?

• solid

• liquid

• gas

• mix of liquid and gas

Multiple Choice

The temperature of this substance is always increasing on this graph.

• true

• false

Multiple Choice

Thermal energy is always being added on this graph.

• true

• false

​It shows how state of matter changes with temperature.

The negative slope means thermal energy is being removed.

Flat lines indicate the temperature is NOT changing, but the matter is changing states.​

​

​

​Cooling

Curve

Multiple Choice

What label is given to the first flat line on the graph?

• temperature

• boiling point

• melting point

• time

Multiple Choice

At the first flat line on the graph, what state of matter should we see?

• mix of solid and liquid

• mix of liquid and gas

• mix of solid and gas

• gas

Multiple Choice

What label is given to the second flat line on the graph?

• temperature

• boiling point

• melting point

• time

Multiple Choice

At the second flat line on the graph, what state of matter should we see?

• solid

• liquid

• mix of solid and liquid

• mix of liquid and gas

Multiple Choice

The temperature of this substance is always decreasing on this graph.

• true

• false

Multiple Choice

Thermal energy is always being removed on this graph.

• true

• false

​Remember!

During a phase change, the temperature does NOT change until every particle has switched phases.

Energy is being removed or added, but temperature does not change.

Temperature changing is demonstrated with the sloped lines.

Phase changing is demonstrated with the flat lines.​

Multiple Choice

Between which points is the temperature of the substance remaining constant?

• A-B only

• A-B, C-D, and E-F

• B-C only

• B-C and D-E

Multiple Choice

The melting point of the sample is

• -60 ºC

• 20 ºC

• 60 ºC

• 100 ºC

Multiple Choice

Which letter indicates where water is in both the solid and liquid phase at the same time?

• A

• B

• C

• D

• E

Multiple Choice

In which region(s) does temperature increase?

• Region C only

• Regions B and D

• Regions A, C, and E

• Regions A and B

Multiple Choice

Describe the substance at letter A.

• Solid

• Liquid

• Melting

• Evaporating

Multiple Choice

What is the freezing point of the substance?

• 0^oC

• 60^oC

• 120^oC

• 180^oC

Multiple Choice

Describe the substance at letter E

Multiple Choice

Given the heating curve of a solid being heated at a constant rate, what is the boiling point of this substance?

• 20°C

• 50°C

• 110°C

• 170°C

​You're finished!

Once you submit, check your grade. If you don't like it, you may redo this assignment to improve your score.​