Separation of Mixtures and Purification of Chemical Substances

These flashcards cover key vocabulary related to the separation of mixtures and purification of chemical substances, as well as the differences between physical and chemical changes.

Mixture

A substance formed when two or more substances are joined together physically.

Decantation

A separation technique used to separate a liquid from solids that have settled at the bottom.

Filtration

A method used to separate solids from liquids using a filter.

Evaporation

The process of turning liquid into vapor, used to separate a soluble solid from a liquid.

Immiscible Liquids

Liquids that do not mix and will separate into different layers when combined.

Distillation

A separation technique used to separate two liquids with widely different boiling points.

Fractional Distillation

A technique for separating two or more miscible liquids with closely different boiling points.

Sublimation

The process where a substance changes from a solid state to a gaseous state without passing through the liquid state.

Chromatography

A method used to separate mixtures based on differences in the rate of movement on an absorbent medium.

Criteria for Purity

Boiling points, melting points, density, and refractive index are used to determine the purity of substances.

Physical Change

A change in which a new substance is not formed and is easily reversible.

Chemical Change

A change in which a new substance is formed and is not easily reversible.

Properties of Pure Substances

Pure substances exhibit sharp or definite melting and boiling points.

Heat Changes in Reactions

Chemical changes often involve large amounts of heat, while physical changes do not.