PChem U1 M1

Mixture

Contains two or more pure substances; can be homogeneous or heterogeneous

Homogeneous

In chemistry, homogeneous refers to a substance or mixture that has a uniform composition throughout. This means that any sample taken from a homogeneous mixture will have the same characteristics and properties, regardless of where it is taken from..

Heterogeneous

In chemistry, "heterogeneous" refers to a mixture that is composed of different constituents or dissimilar components. This means that the composition of a heterogeneous mixture is non-uniform, varying from one location to another within the mixture.

Extensive Properties

Properties that depend on the amount of substance (mass, length)

Intensive Properties

Properties that do not depend on the amount of substance (such as boiling point, density).

Phase Change

The transition of a substance from one state of matter to another, such as solid to liquid or liquid to gas, often involving energy changes.

Kelvin Equation

K = C + 273.15

Sublimation

The process by which a solid turns directly into a gas without passing through the liquid phase

Deposition

The process by which a gas turns directly into a solid

Condensation

Gas —> Liquid

Vaporization

Liquid —> Gas

Melting

Solid —> Liquid

Freezing

Liquid —> Solid

Critical Point

the point at which two phases of a substance initially become indistinguishable from one another. The critical point is the end point of a phase equilibrium curve, defined by a critical pressure T_p and critical temperature P_c. At this point, there is no phase boundary.

Supercritical Fluid

Substance that exhibits properties of both solids and liquids

Triple Point

the unique temperature and pressure at which a substance can exist simultaneously in solid, liquid, and gas phases in thermodynamic equilibrium.

atm

atmospheric pressure

Volatile

easily evaporated

more evaporation =

= more pressure and lower boiling point

Volatility

A measure of how easily a liquid changes to a gas (evaporation)

Work =

= Force x Distance

Unit for energy

joules

760 mm Hg (Mercury) =

= 1 atm