Chemistry Definitions for Test 3

Memorize these definitions

Solution

One or more substances are homogeneously mixed or dissolved in another substance

Solute

The component that is dissolved or is the least abundant component in the solution

Solvent

The dissolving agent or the most abundant component in the solution (what is dissolving)

Miscible

Liquids that are capable of mixing and forming a solution

Immiscible

Liquids that do not form solutions or are generally insoluble in each other

Concentrated Solution

Contains a relatively large amount of dissolved solute

Dilute Solution

Describes a solution that contains a relatively small amount of dissolved solute

Meniscus

When a liquid is placed in a glass cylinder, the surface of the liquid shows a curve called

Colligative Property

Properties that depend only on the number of solute particles in a solution and the nature of those particles

Freezing Point Depression

The decrease in the freezing point of a liquid caused by adding solute

Boiling Point Elevation

The increase in the boiling point of a liquid caused by adding solute

Electronegativity

A measure of the attraction of an atom in a molecule for a pair of shared electrons

Nonpolar Covalent Bond

A covalent bond in which there is an equal sharing of electrons

Polar Covalent Bond

A covalent bond in which more than half of the bond’s negative charge is concentrated around one of the two atoms (unequal sharing of electrons)

Hydrogen Bond

These are formed between polar molecules that contain hydrogen covalently bonded to a small, highly electronegative atom such as fluorine, oxygen, or nitrogen

Dipolar Forces

The attractive forces that exist among polar covalent molecules

Dispersion Forces

The Momentary, usually weak, attractive forces between molecules resulting from synchronized electron motion. These types of forces are used to explain why nonpolar covalent compounds can exist in the liquid and solid states

Ion-Ion

When sodium chloride dissolves in water the ion-ion interactions between sodium and chloride ions must be overcome

Boiling Point

The temperature at which vapor pressure becomes equal to the pressure above a liquid; the temperature at which vapor bubbles form spontaneously any place within a

Freezing or melting point

The temperature at which the solid phase of a substance is in equilibrium with its liquid phase

Evaporation

The escape of molecules from the liquid state to the gas or vapor state is called

Condensation

Molecules in the vapor or gaseous state strike the surface and return to the liquid state by the process of

Sublimation

Solids such as iodine, camphor, naphthalene will go directly from the solid to the gaseous state, bypassing the liquid state. This change is a form of evaporation and is called

Vapor pressure

The pressure or partial pressure exerted by a vapor that is in contact with its liquid phase. Often refers to the pressure or partial pressure of a vapor that is in equilibrium with its liquid state at a given temperature

Volatile

Substances that vaporize easily, have a relatively high vapor pressure at room temperature

Saturated

a homogeneous mixture that contains the maximum amount of dissolved solute that the solvent is capable of dissolving at a given temperature and pressure.

Unsaturated

a homogeneous mixture that contains less dissolved solute than the maximum amount the solvent is capable of dissolving at a given temperature and pressure.

Super saturated

a homogeneous mixture that contains more dissolved solute than the maximum amount the solvent is capable of dissolving at a given temperature and pressure. (these are unstable)

Solubility

shows that unsaturated solutions exist below the curve (more solute can dissolve), saturated solutions lie on the curve (maximum dissolved solute at that temperature), and supersaturated solutions exist above the curve (unstable, contains more than maximum dissolved solute).