Chemistry C1

Matter is classified as either a

Pure substance (element or or compound) or a mixture (Homogenous or heterogeneous)

Homogenous mixtre

A substance in which all components are evenly distributed and have a uniform composition throughout.

Heterogeneous mixture

A mixture in which the components are not uniformly distributed and distinct phases or regions can be observed.

Solubility

The ability of a substance to dissolve in a solvent to form a homogeneous solution at a specified temperature and pressure.

Solubility -Temperature

Solubility generally increases for solids as temperature rises (decreases for gas)

Solubility - pressure

Affects gasses only according to Henrys law gas solubility is directly proportional to the pressure of the gas above the liquid

Solubility - Miscibility

Substances with similar polarities will mix

Saturated solution

A solution is saturated when the concentration of dissolved solute is equal to its solubility, meaning no more solute can dissolve at that temperature

Endothermic

Separating solute or solvent particles is endothermic because it absorbs energy

Exothermic

The interaction between solute and solvent particles is exothermic - it releases energy I

Ionization

Molecular acids (witch contain no ions) react with water to form hydronium and other ions

Dissociation

when a soluble ionic compound breaks in to hydrated free ions

Electrolight

Substance that can conduct electricity in water because they release free ions through dissociation or Ionization

Non electrolight

Can not conduct electricity in water (Most molecular compounds) they do not release ions therefore they do not conduct electricity

Dynamic equilibrium

When the rate of dissolving is exactly equal to the rate of crystallization - resulting in no net change in disolved solute

Solute

The substance being dissolved in a solution, usually present in the smaller quantity

Solvent

The medium in which the solute is dissolved, usually present in the larger quantity (water is the "universal solvent")

Unsaturated Solution

A solution in which the concentration of dissolved solute is less than its solubility, meaning more can be dissolved

Supersaturated Solution

A solution in which the concentration of dissolved solute is greater than its solubility; excess solute will spontaneously crystallize

Endothermic Process

A process that absorbs energy from the surroundings

Exothermic Process

A process that releases energy to the surroundings

Dissociation:

The process where soluble ionic compounds break apart into hydrated, free ions in solution

Ionization

The process where molecular acids react with water to form ions where none existed before