Heating Curves

Copyright © 2011 MsRazz ChemClass

Bell Ringer

Complete the handout
while watching the video.
Use the word bank to help
with labeling the heating
curve

Word Bank:
Solid, Liquid,
Gas, Freezing,
Melting,
Vaporization,
and
condensation.

Copyright © 2011 MsRazz ChemClass

Video

• https://www.bing.com/videos/search?q=tyler+de

witt+phase+changes&&view=detail&mid=C6B29
A29C817C2B5C584C6B29A29C817C2B5C584&&F
ORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3D
tyler%2520dewitt%2520phase%2520changes%26q
s%3DMM%26form%3DQBVR%26sp%3D1%26pq%3D
tyler%2520dewitt%2520phases%26sc%3D1-
19%26cvid%3DAD19A0212B3F4AB4AA40C6EB2446
4693

Copyright © 2011 MsRazz ChemClass

Essential
Question

 Using your picture of the heating curve,

answer what happens to the
temperature of the material when it is
undergoing a phase change?

Copyright © 2011 MsRazz ChemClass

Standard
SC.912.P.10.7

DISTINGUISH BETWEEN ENDOTHERMIC AND EXOTHERMIC
CHEMICAL PROCESSES.

Copyright © 2011 MsRazz ChemClass

After today, you should be able to…

Explain what thermochemistry is

List different types of energy

Explain what happens to particle

motion when heat energy is added

Convert between units of calories

(cal), Joules (J) , and kilo-Joules (kJ)

Copyright © 2011 MsRazz ChemClass

After today you should be able to…

• Explain what occurs on each

point of a heating curve

•Explain the phase changes as

endothermic or exothermic

Copyright © 2011 MsRazz ChemClass

Heating
Curves

When a solid substance is
heated (A), its temperature
will increase until it reaches
its melting point (m.p.).

• Temperature will then stay

constant during the melting
process. (C = liquid) (phase
change=constant
temperature)

Copyright © 2011 MsRazz ChemClass

Heating Curves

A heating curve is a graph of
temperature versus time.
•It describes the enthalpy
changes that take place
during phase changes.

Copyright © 2011 MsRazz ChemClass

Copyright © 2011 MsRazz ChemClass

Endothermic and
Exothermic & Phase
Changes

•Sublimation, when a solid
transforms into a gas, is
an endothermic phrase change,

•Deposition, when a gas transforms
to a solid, is an exothermic phase
change.

•There are a total of
six phase changes in matter, and
three are endothermic and three
are exothermic

Copyright © 2011 MsRazz ChemClass

Heating
Curves

When a substance is
completely melted, its
temperature will again
increase until it has
reached its boiling point
(b.p.).

• Temperature stays

constant during boiling.

• Once completely

vaporized, the
temperature will again
increase. (E=gas)

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

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

A measure of the average kinetic energy of the particles in an object is called

• Heat

• Temperature

• Kinetic energy

• Enthalpy

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

The energy transferred between objects that are at different temperatures is called

• Heat

• Temperature

• Energy

• Friction

Multiple Choice

Describe the substance at letter A.

• Solid

• Liquid

• Melting

• Evaporating

Multiple Choice

At which letter is the substance changing its state of matter?

• A only

• A, C, and E

• D and E

• B and D

Multiple Choice

The melting point of the sample is

• -60 ºC

• 20 ºC

• 60 ºC

• 100 ºC

Multiple Choice

__________ show the change in state of matter as heat is added.

• Phase diagrams

• Heating curves

• Density graphs

• Temperature plots