Chapter 6 - Mixtures

Question 1

Adsorption

Answer 1

To form a bond with the surface of something. In chromatography, a sample sticking to the solid stationary phase.

Question 2

Chromatogram

Answer 2

A pattern or band produced during chromatography.

Question 3

Chromatography

Answer 3

A technique used to separate the different substances in a mixture, by relying on them having different solubilities.

Question 4

Desorption

Answer 4

To break a bond that has been formed with the surface of something. In chromatography, a sample dissolving in the mobile phase.

Question 5

Dissociation

Answer 5

The process of water molecules pulling the ions apart in an ionic lattice.

Question 6

Homogeneous

Answer 6

(Of a substance) evenly distributed, as in the homogeneous solute in a solution.

Question 7

Hydrated

Answer 7

A substance that is surrounded by water molecules.

Question 8

Hydronium Ion

Answer 8

An ion formed when covalent substances without hydrogen bonds react with water molecules. H3O+.

Question 9

Immiscible

Answer 9

Two liquids that do not dissolve in each other. I.e. a polar and a non-polar liquid.

Question 10

Hydrolysis

Answer 10

A chemical reaction in which a water molecule breaks the chemical bonds of another molecule or compound.

Question 11

Ionisation

Answer 11

The process of creating an ion, such as through ionic bonding or when a molecule with a polar bond is dissolved in water.

Question 12

Ion-dipole Attraction

Answer 12

The electrostatic attraction between a charged ion and a water molecule.

Question 13

Ionised

Answer 13

An atom or molecule that has produced ions, such as HCl when it dissolves in water.

Question 14

Miscible

Answer 14

Two liquids that dissolve in each other. I.e. two polar or two non-polar liquids.

Question 15

Mobile Phase

Answer 15

The liquid or gas in chromatography that moves the sample.

Question 16

Stationary Phase

Answer 16

A solid or liquid in chromatography that does not move, which the sample adsorbs onto.

Question 17

Origin

Answer 17

The starting point on a chromatography stationary phase where a sample is placed.

Question 18

Retention Factor

Answer 18

The distance moved by a sample from the origin, divided by the distance moved by a solvent from the origin.

Question 19

Solute

Answer 19

The substance that is dissolved in the solvent.

Question 20

Solvent

Answer 20

The substance that the solute is dissolved in.

Question 21

Paper Chromatography

Answer 21

Chromatography where the stationary phase is a piece of porous paper, such as filter paper.

Question 22

Thin Layer Chromatography (TLC)

Answer 22

Chromatography where the stationary phase is a glass, metal or plastic plate with a thin layer of aluminum oxide (alumina) applied.

Question 23

Standards (Identification)

Answer 23

A chemical substance whose identify is known, which is added to a chromatography sample for comparison.

Question 24

Formula for Dissolving an Ion

Answer 24

XY (s) → X+ (aq) + Y- (aq)
h2o above arrow

Question 25

Formula for Dissolving a Molecule (with hydrogen bonds)

Answer 25

XYZ (s) → XYZ (aq)
h2o above arrow

Question 26

Formula for Dissolving a Molecule (with hydrogen but without hydrogen bonds)

Answer 26

XH (s) + H2O (l) → H3O+ (aq) + X- (aq)