Liquids and Solids

Phase Diagrams

How do substances change state?Beginning State Ending State Process of Change

Solid Liquid Melting

Solid Gas Sublimation

Liquid Solid Freezing

Liquid Gas Vaporization

Gas

Gas

Solid

Liquid Condensation

Deposition

Water phase changesThe temperature remains constantduring a phase change.

Phase DiagramPhase Diagram:Phase Diagram: represents the phases as a represents the phases as a function of temperature and pressure. function of temperature and pressure.Critical temperatureCritical temperature: temperature above: temperature above which the vapor can not be liquefied. which the vapor can not be liquefied.Critical pressureCritical pressure: pressure required to liquefy at: pressure required to liquefy at the critical temperature. the critical temperature.Critical pointCritical point: This point specifies the: This point specifies the conditions of temperature and pressure at conditions of temperature and pressure at which the liquid state of the substance ceases which the liquid state of the substance ceases to exist. Beyond this point a gas cannot be to exist. Beyond this point a gas cannot be liquefied no matter how much pressure is liquefied no matter how much pressure is applied. applied.

Phase Diagram with Changes by Name

Phase Diagram of Water

temperature

pressure

solid liquid

gas.

FREEZE

MELT CONDENSATION

VAPORIZATION

SUBLIMATIONDEPOSITIO

N

B

temperature

pressure

A

C

D

solid liquid

gas.

A: Triple point – the temperature and pressure at which gas, liquid, and solid form of a substance all exist in equilibrium.B: Melting curveC: Vaporization curveD: Sublimation curveE: Critical point – the temperature and pressure above which gas cannot be liquefied no matter how much pressure is applied.

E

Water

Carbon dioxide

Carbon

Sulfur

Phase Diagrams• Be able to label phases on a phase diagram: gas Be able to label phases on a phase diagram: gas

(vapor), liquid, solid A, solid B, solid C, etc.(vapor), liquid, solid A, solid B, solid C, etc.• Be able to label parts of a phase diagram: triple Be able to label parts of a phase diagram: triple

point, critical point, melting curve, vaporization point, critical point, melting curve, vaporization curve, sublimation curve.curve, sublimation curve.

• Be able to label arrows on a phase diagram: Be able to label arrows on a phase diagram: melting, freezing, vaporization, condensation, melting, freezing, vaporization, condensation, sublimation, deposition.sublimation, deposition.

• For a given temperature and pressure, be able to For a given temperature and pressure, be able to identify the phase: gas, liquid, solid A, solid B, etc.identify the phase: gas, liquid, solid A, solid B, etc.