AQA A Level Chemistry: Inorganic

Metallic (elements)

Sodium, magnesium and aluminium

Semi-metal (metalloid) (elements)

Silicon

Non-metals (elements)

Phosphorus, sulfur and chlorine

Noble gas (elements)

Argon

Metallic (Description)

Shiny, conduct electricity, react with dilute acids to give hydrogen and salts

Semi-metal (metalloid) (Description)

Conducts electricity to some extent, useful form making semiconductor devices

Non-metals (Description)

Don't conduct electricity and have low melting and boiling points

Noble gas (Description)

Chemically unreactive and exists as separate atoms

2Na + 2H2O --> 2NaOH + H2

Sodium + water reaction

Mg + 2H2O --> Mg(OH)2 + H2

Magnesium + water reaction

Mg + H2O --> MgO + H2

Magnesium + steam reaction

4Na + 2O2 --> 2Na2O

Sodium + oxygen reaction

2Mg + O2 --> 2MgO

Magnesium + oxygen reaction

4Al + 3O2 --> Al2O3

Aluminium + oxygen reaction

Si + O2 --> SiO2

Silicon + oxygen reaction

4P + 5O2 --> P4O10

Phosphorus + oxygen reaction

S + O2 --> SO2

Sulfur + oxygen reaction

Allotropes

Pure elements which can exist in different physical forms in which their atoms are arranged differently.

Na2O (Name)

Sodium oxide

Na2O (Bonding)

Ionic bonding

Na2O (Structure)

Giant ionic structure

Na2O (pH)

Strongly alkaline (pH 13-14)

Na2O (Acid or base)

Basic

MgO (Name)

Magnesium oxide

MgO (Bonding)

Ionic bonding

MgO (Structure)

Giant ionic structure

MgO (pH)

Weaker alkaline (pH 10)

MgO (Acid or base)

Basic

Al2O3 (Name)

Aluminium oxide

Al2O3 (Bonding)

Ionic/covalent bonding

Al2O3 (Structure)

Giant ionic structure

Al2O3 (Acid or base)

Amphoteric

SiO2 (Name)

Silicon dioxide

SiO2 (Bonding)

Covalent bonding

SiO2 (Structure)

Giant covalent (macromolecular) structure

SiO2 (Acid or base)

Acidic

P4O10 (Name)

Phosphorus pentoxide (Phosphorus (V) oxide)

P4O10 (Bonding)

Covalent bonding

P4O10 (Structure)

Molecular structure

P4O10 (pH)

Fairly strong acid (pH 1-2)

P4O10 (Acid or base)

Acidic

SO3 (Name)

Sulfur trioxide

SO3 (Bonding)

Covalent bonding

SO3 (Structure)

Molecular structure

SO3 (pH)

Strong acid (pH 0-1)

SO3 (Acid or base)

Acidic

SO2 (Name)

Sulfur dioxide

SO2 (Bonding)

Covalent bonding

SO2 (Structure)

Molecular structure

SO2 (pH)

Weak acid (pH 2-3)

SO2 (Acid or base)

Acidic

Na2O + H2O --> 2NaOH

Sodium oxide + water

MgO + H20 --> Mg(OH)2

Magnesium oxide + water

P4O10 + H2O --> 4H3PO4

Phosphorus pentoxide + water

SO2 + H2O --> H2SO3

Sulfur dioxide + water

SO3 + H2O --> H2SO4

Sulfur trioxide + water

Na2O + HCl --> 2NaCl + H2O

Sodium oxide + HCl

MgO + 2HCl --> MgCl2 + H2O

Magnesium oxide + HCl

Al2O3 + 6HCl --> 2AlCl3 + 3H2O

Aluminium oxide (as a base) + HCl

Al2O3 + 2NaOH + 3H2O --> 2Na+[Al(OH)4]-

Aluminium oxide (as an acid) + NaOH

SiO2 + 2NaOH --> Na2SiO3 + H2O

Silicon dioxide + NaOH

P4O10 + 12NaOH --> 4Na3PO4 + 6H2O

Phosphorus pentoxide + NaOH

SO2 + 2NaOH --> Na2SO3 + H2O

Sulfur dioxide + NaOH

SO3 + 2NaOH --> Na2SO4 + H2O

Sulfur trioxide + NaOH

Amphoteric

A substance that can act as both an acid and a base

2SO2 + O2 <--> 2SO3

The contact process (V2O5 catalyst)

Transition element

An element that forms at least one stable ion with a part filled d-orbital of electrons

Co-ordinate bond

A covalent bond in which both of the electrons in the bond come from one of the atoms forming the bond

Dative bond

A covalent bond in which both of the electrons in the bond come from one of the atoms forming the bond

Ligand

An atom, ion or molecule that forms a co-ordinate (dative) bond with a transition metal ion using a lone pair of electrons

Co-ordination number

The number of ligand molecules bonded to a metal ion

Octahedral

90 degrees

Co-ordination number: 6

Tetrahedral

109.5 degrees

Co-ordination number: 4

Square planar

90 degrees

Co-ordination number: 4

Linear

180 degrees

Co-ordination number: 2

Aqua ions

A transition metal ion surrounded by (usually 6) water molecules acting as ligands

Multidentate ligand

A ligand that has more than one atom with a lone pair of electrons which can bond to a transition metal ion

Chelates

Complex ions with polydentate ligands

Chelate effect

Chelate complexes with polydentate ligands are favoured over complexes with monodentate ligands

Geometrical isomer

Ligands differ in their position in space relative to one another

Optical isomer

Two isomers are non-superimposable mirror images of each other

Chiral

A molecule that exists in two mirror image forms that are not superimposable

Green

[Fe(H2O)6]2+ colour

Pale brown

[Fe(H2O)6]3+ colour

Blue

[Cr(H2O)6]2+ colour

Red-violet

[Cr(H2O)6]3+ colour

Brown

[Co(NH3)6]2+ colour

Yellow

[Co(NH3)6]3+ colour

5Fe2+ + MnO4- + 8H+ --> 5Fe3+ + Mn2+ + 4H2O

Potassium manganate + iron (II)

Heterogeneous

Catalyst in a reaction in a different phase than the reactants

N2 + 3H2 <--> 2NH3 (iron catalyst)

Haber process

Iron

Catalyst in Haber process

SO2 + V2O5 --> SO3 + V2O4

First step of the Contact process

2V2O4 + O2 --> 2V2O5

Second step of the Contact process (regeneration of the catalyst)

V2O5

Catalyst for the Contact process

V2O5

Vanadium(V) oxide

Homogeneous

Catalyst in reaction in the same phase as the reactants, intermediate species formed

Autocatalysis

When one of the products of a reaction is the catalyst for that reaction

2MnO4- + 5(C2O4)2- + 16H --> 2Mn2+ + 8H2O + 10CO2

Oxidation of ethanoic acid by manganate (VII) ions

[Fe(H2O)6]3+ <--> [Fe(H2O)5(OH)]2+ + H+

Hydrolysis with Fe3+