AP CHEMISTRY SEMSESTER EXAM REVIEW

matter

anything with mass and volume

pure substances

cannot be separated by physical means

Elements

Pure substance than cannot be broken down chemically or physically

Compounds

Pure substance that can be broken down chemically but not physically

Diatomic elements

If by itself, only exists as 2 atom molecules , H2, N2, O2, F2, Cl2, Br2, I2

Mixtures

can be separated by physical means

Heterogenous Mixture

Don’t look the same throughout

Suspension

Heterogeneous mixture in which there are large particles, ex: mud water

Homogenous Mixture

Looks the same throughout

Colloid

medium particles, ex: milk, jello

Tyndall Effect

the scattering of light off of large enough particles

Extensive property

a property dependent on the amount, ex: volume, length, surface area

Intensive property

a property independent of the amount, ex: color, odor, reactivity

Physical property

A property that can be observed without changing the chemical composition of a substance, ex: color

Chemical property

A property that can be observed only by changing the chemical composition of the substance, ex: reactivity

Physical change

a change that does not affect the chemical composition of the substance, ex: dissolving

Chemical change

a change that alters the chemical composition of the substance, ex; burning

Direct separation

A manual separation of mixture parts based on some macroscopic or large-scale property. Ex: separation of oil from water (solubility), red blocks from yellow blocks (color), and iron from sulfur (magnets)

Filtration

A process for separating a solid-liquid mixture by passing it through a barrier with fine pores like filter paper. Ex: filtering sand from water

Evaporation

A process of separation used to separate moisture from a solution or evaporate one substance from another. Ex: salt in water

Distillation

A process where a liquid is vaporized under conditions where the evolved vapor is later condensed and collected, separation is do to different boiling points.

Crystallization

To separate from a solution the solid components as the solution is either evaporated or cooled enough to cause crystals of the less soluble solids to form from the solution

Chromatography

A separation method where a solvent and a solute are put together and the solute will travel furthest with the most alike solvent