Expressions of Concentrations

System

-is generally considered to be a bounded space or an exact quantity of a material substance.

Dispersion

-consists of at least two phases with one or more dispersed (internal) phases contained in a single continuous (external) phase.

Phase

-a distinct homogenous part of a system separated by a definite boundaries from other parts of a system.

True Solutions

-defined as a mixture of two or more components that form a homogenous molecular dispersion.

HOMOGENOUS

SOLUTION

is a _______________ mixture of 2 or more substances in a single phase. One constituent is usually regarded as the SOLVENT and the others as SOLUTES.

SOLUTE

– the part of a solution that is being dissolved (usually the lesser amount)

SOLVENT

– the part of a solution that dissolves the solute (usually the greater amount

saturated solution

contains the maximum quantity of solute that dissolves at that temperature

unsaturated solution

contains less than the maximum amount of solute that can dissolve at a particular temperature.

supersaturated solution

contains more than the maximum amount of solute that a solvent can dissolve at a given temperature.

IONIC COMPOUND

Many reactions involve ionic compounds, especially reactions in water — aqueous solutions.

Nonelectrolytes

are substances that do not ionize when dissolved in water and therefore do not conduct an electric current through the solution

Electrolytes-

are substances that form ions in solution, conduct electric current, and show apparent “anomalous” colligative properties

1. CONDUCTIVITY testing

2. SOLUBILITY testing

How do we know ions are present in aqueous solutions?

HCl, MgCl2, and NaCl

=are strong electrolytes.

Ephedrine and Phenobarbital

= are Weak electrolytes

called nonelectrolytes.

Some compounds dissolve in water but do not conduct electricity. They are??

Examples include: sugar glycerine naphthalene urea

Non-electrolytes

◉ Substances that do not yield ions when dissolved in water

◉ Examples of non-electrolytes are sucrose, glycerin, naphthalene, and urea.

◉ A 0.1-molar solution of non-electrolyte produces approximately the same colligative effect as any other non-electrolytic solution of equal concentration

TRUE SOLUTION

form HOMOGENOUS

• PS: Less than 1 namometer

Greater than 0.5 micrometer

Coarse Dispersion PS

1un - 0.5um

Colloidal dispersion PS

Colloidal dispersion

intermidiate between true s and couarse d.

IONIZATION

Process that ION GAIN or LOSS electron

Nega

ANION

GAIN electron

=

=

poti

CATION

LOSS electron

=

=