Chemistry 13.4

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Transcript Chemistry 13.4

Chemistry 17.4
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13.4
Changes of State
Familiar weather events can remind
you that water exists on Earth as a
liquid, a solid, and a vapor. As
water cycles through the
atmosphere, the oceans, and
Earth’s crust, it undergoes repeated
changes of state. You will learn
what conditions can control the
state of a substance.
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13.4
Changes of State
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Sublimation
Sublimation
When can sublimation occur?
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13.4
Changes of State
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Sublimation
The change of a substance from a solid to a
vapor without passing through the liquid state is
called sublimation.
Sublimation occurs in solids with vapor
pressures that exceed atmospheric
pressure at or near room temperature.
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13.4
Changes of State
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Sublimation
When solid iodine is
heated, the crystals
sublime, going directly
from the solid to the
gaseous state. When the
vapor cools, it goes
directly from the gaseous
to the solid state.
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Changes of State
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Sublimation
Simulation 14
Predict the physical states present at different
points on a phase diagram.
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13.4
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Phase Diagrams
Phase Diagrams
How are the conditions at which phases
are in equilibrium represented on a
phase diagram?
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13.4
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Phase Diagrams
A phase diagram is a graph that gives the
conditions of temperature and pressure at
which a substance exists as solid, liquid, and
gas (vapor).
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Phase Diagrams
The conditions of pressure and
temperature at which two phases exist in
equilibrium are indicated on a phase
diagram by a line separating the phases.
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13.4
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Phase Diagrams
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Phase Diagrams
The triple point describes the only set of
conditions at which all three phases can exist in
equilibrium with one another.
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13.4 Section Quiz.
Assess students’ understanding
of the concepts in Section 13.4.
Continue to:
-or-
Launch:
Section Quiz
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13.4 Section Quiz.
1. Identify the change of state that occurs when
solid CO2 changes to CO2 gas as it is heated.
a. condensation
b. freezing
c. vaporization
d. sublimation
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13.4 Section Quiz.
2. Sublimation occurs in solids if the vapor
pressure at or near room temperature
a. exceeds atmospheric pressure.
b. equals atmospheric pressure.
c. is less than atmospheric pressure.
d. is less than half the atmospheric pressure.
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13.4 Section Quiz.
3. What is the significance of a line in a phase
diagram?
a. Only one phase is present.
b. Two phases are in equilibrium.
c. Three phases are in equilibrium.
d. The distinction between two phases
disappears.
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13.4 Section Quiz.
4. What is the significance of the triple point in a
phase diagram?
a. Temperature and pressure are equal.
b. Two phases are in equilibrium.
c. Three phases are in equilibrium.
d. The distinction among three phases
disappears.
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Changes of State
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Concept Map 13
Solve the Concept Map with the help of an
interactive guided tutorial.
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END OF SHOW