Reaction with Oxygen
Oxide Formation
- The period 3 elements, excluding chlorine and argon, combine with oxygen to form oxides
- The oxide formed will contain the elements in their highest oxidation state
- The following equations show these reactions:
4Na (s) + O2 (g) → 2Na2O (s)
2Mg (s) + O2 (g) → 2MgO (s)
4Al (s) + 3O2 (g) → 2Al2O3 (s)
Si (s) + O2 (g)→ SiO2 (s)
4P (s) + 5O2 (g) → P4O10 (s)
S (s) + O2 (g) → SO2 (g)
Reaction of Period 3 elements with oxygen table
- Sulfur can actually form two oxides - SO2 and SO3
- For SO3 to form, a catalyst must be used and the reaction must take place at a very high temperature
- The equation for this reaction is:
2S (s) + 3O2 (g) → 2SO3 (g)
- The oxides formed from these reactions have different physical properties, depending on the type of structure and bonding
- Sodium oxide, magnesium oxide and aluminium oxide are all ionic oxides
- Sodium, magnesium and aluminium are all metals and oxygen is a non-metal
- Silicon oxide has a giant covalent structure, like diamond
- Phosphorus oxide and sulfur dioxide are simple covalent molecules