AQA A2 Unit 5 - Periodicity 3.5.2

The elements from Sodium (Na) to Argon (Ar).
Their reactions with water and oxygen.
Their oxides reactions with oxygen and water, their pH in solution and their reaction with acids and bases.

?

Na - Sodium

Metallic Structure.
(can conduct electricity because of delocalised electrons)

Reacts vigorously with water to form NaOH.

Reacts vigorously with oxygen to form its oxide Na2O.

Na2O forms a giant ionic lattice.

pH of oxide in water is 14
(forms NaOH when reacted with water)

Reacts with acids:
With monoprotic acids --> NaX + H2O
With diprotic acids --> Na2X H2O

1 of 8

Mg - Magnesium

Metallic Structure.
(can conduct electricity because of delocalised electrons)

Reacts vigorously with steam to form MgO and hydrogen.

Reacts vigorously with oxygen (brilliant white flame) to form its oxide MgO.

MgO forms a giant ionic lattice.

pH of oxide in water is 10
(forms Mg(OH)2 when reacted with water)

Reacts with acids:
MgO + 2HCl --> MgCl2 + H2O

2 of 8

Al - Aluminium

Metallic Structure.
(can conduct electricity because of delocalised electrons)

Doesn't react with water because of a protective oxide layer.

Powdered aluminium reacts with oxygen to form its oxide Al2O3.

Al2O3 forms a giant ionic lattice with strong covalent character.

pH of oxide in water is 7 and it is amphoteric.
(is insoluble in water)

Reacts with acids and bases:
Al2O3 + 6HCl --> 2AlCl3 + 3H2O
Al2O3 + 2NaOH + 3H2O --> 2NaAl(OH)4

3 of 8

Si - Silicon

Giant Covalent Structure.

Doesn't react with water because of a protective oxide layer.

No reaction with oxygen until 900'C where it forms SiO2.

pH of oxide in water is 7.
(is insoluble in water)

Reacts with bases:
SiO2 + 2NaOH --> Na2SiO3 + H2O

4 of 8

P - Phosphorus

Simple Molecular Structure.

Doesn't react with water.

Reacts spontaneously with oxygen to form its oxide P4O10.

P4O10 forms a molecular structure with covalent bonding.

pH of oxide in water is 0.
(reacts with water to form H3PO4)

Reacts with bases:
P4O10 + 12NaOH --> 4Na3PO4 + 6H2O

5 of 8

S - Sulphur

Simple Molecular Structure.

It doesn't react with water.

Melts easily in oxygen and burns with a blue flame to form SO2.

SO2 forms a molecular structure with covalent bonding.

pH of oxide in water is 3 for SO2 and 0 for SO3.
(SO2 forms H2SO3 when it reacts with water, SO3 forms H2SO4 when it reacts with water)

Reacts with bases:
SO2 + CaCO3 --> CaSO3 + CO2

6 of 8

Cl - Chlorine

Simple Molecular Structure.

It reacts with water to form HCl and HClO (disproportionation).

Doesn't react with oxygen.

7 of 8

Ar - Argon

Monatomic Structure with Van der Waals forces.

It doesn't react with water.

It doesn't react with oxygen.

8 of 8

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Acids, bases and salts resources »