Phase Diagram

The state of matter of a substance is dependent

on 2 variables.

- Temperature- Pressure

You can use a Phase Diagram to determine the state of matter of a substance, depending

on it’s temperature and pressure.

Typical Phase Diagram

Important Parts of

the Phase Diagram

Melting Curve –

shows the pressure and temperature that a solid becomes a liquid and visa versa.

Vapor Curve – shows the

pressure and temperature that a liquid

becomes a gas and visa versa.

Sublimation Curve – shows

the pressure and

temperature that a solid

becomes a gas and visa versa.

Triple Point – is the

temperature and pressure where all 3 phases of matter can

coexist.

Critical Point – occurs under conditions at

which no phase boundaries exist.

Phases Diagram for

H2O

At 1 atm H2O melts at 0oC and boils at

100oC.

What state of matter would the following substance be under

the following conditions?

Temp. = - 20oC Press. = 100atm

Temp. = -70oC Press. = 1000atm

Temp. = 0oC Press. = 1atm

What phase change would occur under

the following conditions?

Temp. = -20 Press. = 1 atm to 100 atm

Temp. = 10 Press. = 100 atm to 10,000 atm

Temp. = -70 Press. = 1 atm to 10 atm

Temp. = -20 Press. = 5000 atm to 1 atm

Temp. = -100 to -60 Press. = 1 atm

Temp. = -60 to -40 Press. = 100 atm

Temp. = -50 to 0 Press. = 10 atm

On the bottom of your notes answer

the following questions.

What state of matter would you have at a temp. of 200oC and a

pressure of 0.50 atm?

What state of matter would you have at a temp. of 400oC and a

pressure of 1.50 atm?

What state of matter would you have at a temp. of 100oC and a

pressure of 2.0 atm?

What phase change would occur if the temp. was a constant 300oC and the pressure decreased from 1.25 to 0.5

atm?

What phase change would occur if the pressure was a constant 1.25 atm and the temp. increased from 0 to 800oC?

What temperature and pressure can all 3 phases exist at once?

Use the information you just got to complete the ‘Phase Diagram

Practice Sheet 1213’ .

Due tomorrow (10 pts.)

Individual Work!!

Once finished with the worksheet:

- Complete the Gizmo worksheet and quiz

- Complete the Kinetic Theory and Endo/Exo. Practice Sheet and put it in

the appropriate dropbox.