AP Chemistry : Phase Diagrams

Study concepts, example questions & explanations for AP Chemistry

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Example Questions

Example Question #1 : Phase Diagrams

What is the definition of the triple point?

Possible Answers:
The condensation line of the phase diagram
The state where liquid and gas cannot be differentiated
None of these
The point in which temperature change has no effect on the substance
The state where solid, liquid, and gas coexist in equilibrium
Correct answer: The state where solid, liquid, and gas coexist in equilibrium

Definition of triple point: where solid, liquid, and gas exist in equilibrium

Example Question #15 : Phase Changes

What is represented by point D

Possible Answers:

Critical point

liquid phase


Triple point


Correct answer:

Critical point


the critical point is where the solid and gas cannot be distinguished

Example Question #16 : Phase Changes

A solution of water is at 0.006atm and 0.01 degrees Celsius. What phase(s) are present in the sample?


Possible Answers:

Liquid only

Solid and liquid

Liquid and gas

Solid and gas

Solid, liquid, and gas

Correct answer:

Solid, liquid, and gas


The point detailed in the question is the triple point of water on the phase diagram. At the triple point all three phases of a chemical coexist; as such the correct answer is solid, liquid, and gas. 

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