Chapter 6 - Mixtures Flashcards
Adsorption
To form a bond with the surface of something. In chromatography, a sample sticking to the solid stationary phase.
Chromatogram
A pattern or band produced during chromatography.
Chromatography
A technique used to separate the different substances in a mixture, by relying on them having different solubilities.
Desorption
To break a bond that has been formed with the surface of something. In chromatography, a sample dissolving in the mobile phase.
Dissociation
The process of water molecules pulling the ions apart in an ionic lattice.
Homogeneous
(Of a substance) evenly distributed, as in the homogeneous solute in a solution.
Hydrated
A substance that is surrounded by water molecules.
Hydronium Ion
An ion formed when covalent substances without hydrogen bonds react with water molecules. H3O+.
Immiscible
Two liquids that do not dissolve in each other. I.e. a polar and a non-polar liquid.
Hydrolysis
A chemical reaction in which a water molecule breaks the chemical bonds of another molecule or compound.
Ionisation
The process of creating an ion, such as through ionic bonding or when a molecule with a polar bond is dissolved in water.
Ion-dipole Attraction
The electrostatic attraction between a charged ion and a water molecule.
Ionised
An atom or molecule that has produced ions, such as HCl when it dissolves in water.
Miscible
Two liquids that dissolve in each other. I.e. two polar or two non-polar liquids.
Mobile Phase
The liquid or gas in chromatography that moves the sample.
Stationary Phase
A solid or liquid in chromatography that does not move, which the sample adsorbs onto.
Origin
The starting point on a chromatography stationary phase where a sample is placed.
Retention Factor
The distance moved by a sample from the origin, divided by the distance moved by a solvent from the origin.
Solute
The substance that is dissolved in the solvent.
Solvent
The substance that the solute is dissolved in.
Paper Chromatography
Chromatography where the stationary phase is a piece of porous paper, such as filter paper.
Thin Layer Chromatography (TLC)
Chromatography where the stationary phase is a glass, metal or plastic plate with a thin layer of aluminum oxide (alumina) applied.
Standards (Identification)
A chemical substance whose identify is known, which is added to a chromatography sample for comparison.
Formula for Dissolving an Ion
XY (s) → X+ (aq) + Y- (aq)
h2o above arrow
Formula for Dissolving a Molecule (with hydrogen bonds)
XYZ (s) → XYZ (aq)
h2o above arrow
Formula for Dissolving a Molecule (with hydrogen but without hydrogen bonds)
XH (s) + H2O (l) → H3O+ (aq) + X- (aq)
