Unit 5 Key Words

Question 0

First ionisation enthalpy

Answer 0

Enthalpy change when one electron is removed from each of a mole of free gaseous atoms of that element

Question 1

Enthalpy of Formation

Answer 1

Enthalpy change when one mole of a compound is formed from it’s elements in their standard states

Question 2

Second ionisation energy

Answer 2

Enthalpy change when one electron is removed from each of a mole of free gaseous unipositive ions of that element

Question 3

Enthalpy of atomisation of an element

Answer 3

Enthalpy change when one mole of free gaseous atoms is produced from that element in it’s standard state

Question 4

Enthalpy of atomisation of a compound

Answer 4

Enthalpy change when one mole of a compound in it’s standard state is converted into free gaseous atoms

Question 5

First electron affinity

Answer 5

Enthalpy change when one electron is added to each of a mole of free gaseous atoms of that element

Question 6

Second electron affinity

Answer 6

Enthalpy change when one electron is added to each of a mole of free gaseous uninegative ions of that element

Question 7

Bond dissociation enthalpy

Answer 7

Mean enthalpy change she one mole of covalent bonds is broken homolytically, resulting in free gaseous atoms

Question 8

Lattice enthalpy

Answer 8

Enthalpy change when one mole of an ionic compound is formed from it’s free gaseous atoms

Question 9

Lattice dissociation enthalpy

Answer 9

Enthalpy change when one mole of an ionic compound is completely dissociated into free gaseous ions

Question 10

Enthalpy of hydration

Answer 10

Enthalpy change when one mole of free gaseous ions is added to an excess of water

Question 11

Enthalpy of solution

Answer 11

Enthalpy change when one mole of an ionic compound is completely dissolved in an excess of water

Question 12

Entropy

Answer 12

A measure of the degree of disorder in a substance

Question 13

Spontaneous reaction

Answer 13

A reaction for which the free energy change is negative

Question 14

Amphoteric

Answer 14

Able to react with acids and alkalis

Question 15

Oxidation number

Answer 15

The charge that would exist on an atom if all the bonding were completely ionic

Question 16

Standard electrode potential

Answer 16

The emf of a cell in which the left-hand electrode is the standard hydrogen electrode and the right-hand electrode is the standard electrode in question

Question 17

Ligand

Answer 17

A species which can use it’s lone pair of electrons to form a co-ordinate bond with a metal ion

Question 18

Co-ordinate number

Answer 18

The total number of co-ordinate bonds formed between the metal ion and the ligands in a complex

Question 19

Complex

Answer 19

A species containing a metal ion attached to one or more ligands by means of co-ordinate bonds

Question 20

Bidentate ligand

Answer 20

A ligand which uses two lone pairs of electrons to form two co-ordinate bonds with a metal ion

Question 21

Multidentate ligand

Answer 21

A ligand which uses more than two lone pairs of electrons to form more than two co-ordinate bonds with a metal ion

Question 22

Homogeneous catalyst

Answer 22

A catalyst in the same physical state as the reactants

Question 23

Heterogeneous catalyst

Answer 23

A catalyst in a different physical state to the reactants

Question 24

Lewis acid

Answer 24

An electron pair receptor

Question 25

Lewis base

Answer 25

An electron pair donor