Chemistry of the Dissolving Process and Solubility

Flashcards covering the molecular mechanisms of dissolving, types of solutions, and factors affecting solubility such as temperature and pressure.

Hydration

The process where ions leave a crystal and become surrounded by a sphere of water molecules, which stabilizes the ions in solution and prevents them from attracting each other.

Dissociation

The process in which ions separate from ionic crystals to become individual ions.

(aq)

A symbol used in chemical equations to indicate that ions are hydrated or dissolved in water.

Miscible

A term describing liquids that mix with each other in all proportions, such as ethanol and water.

Immiscible

A term describing liquids that do not mix with each other, such as oil and water.

Electronegativity

A property describing the ability of an atom to attract electrons in a bond.

Surfactant

Also known as a surface acting agent, this substance reduces the surface tension of a liquid by breaking down the hydrogen bonding network at the surface.

Like dissolves like

A summary principle stating that solutes dissolve in solvents of similar polarities; for example, ionic and polar covalent compounds are soluble in polar solvents.

Solubility

The quantity of solute that can dissolve in a given quantity of solvent, typically expressed per $100\,g$ of water.

Saturated solution

A solution that contains the maximum quantity of solute at a given temperature.

Unsaturated solution

A solution that contains less than the maximum quantity of solute possible at a specific temperature.

Supersaturated solution

An unstable solution that contains more dissolved solute than it normally would at a given temperature.

Solubility curve

A graph plotting the solubility of a given solute against temperature; points on the curve represent saturated solutions, while points below represent unsaturated solutions.

Thermal pollution

The release of excess thermal energy into water, such as industrial discharge, which can reduce dissolved oxygen concentrations to levels stressful for aquatic life.

Pressure

The force applied to a unit area; while it has little effect on solids or liquids, the solubility of a gas in a liquid increases as this property increases.