Ionic Bond and Sodium Peroxide

Formula of oxide
Na2O2
MgO
Al2O3
SiO2
P4O10
Cl2O
Melting Point
(C)
460
2825
2072
1700
340
-120.6
Boiling Point
(C)
657
3600
2977
2230
360
2.2
State at STP
Solid
Solid
Solid
Solid
Solid
Liquid
Action of water
Dissolve in water and form alkaline solution
Slightly dissolve in water and form alkaline solution
Insoluble in water
Insoluble in water
Dissolve in water and form acidic solution
Dissolve in water and form acidic solution pH of aqueous solution
14
9
7
7
1
3
Acid-base nature
Basic
Basic
Amphoteric
Acidic
Acidic
Acidic
Conductivity of liquid
Conductor
Conductor
Conductor
Insulator
Insulator
Insulator
Solubility in hexane
Insoluble
Insoluble
Insoluble
Soluble
Soluble
Soluble
Structure
Giant ionic structure
Giant ionic structure
Ionic with covalent character
Giant covalent structure
Simple molecular structure
Simple molecular structure
Bonding
Ionic bonding
Ionic bonding
Ionic bonding
Covalent bonding
Covalent bonding
Covalent bonding

Boiling point is the temperature at which the vapor pressure of the liquid is equal to the external pressure on the liquid and the liquid changes into a vapor. Melting point is the temperature at which the lattice is collapses and the solid is converted into liquid. The trend in structure is from the metallic oxides containing giant structures of ions on the left of the period via a giant covalent oxide in the middle to molecular oxides on the right. Sodium peroxide, magnesium oxide and aluminum oxide are metallic oxide which have high melting and boiling point compared to other period 3 oxide. This is due to their giant ionic structure and the strong ionic bond. Strong ionic bond in the molecule need more energy to overcome it. Therefore, the more energy required, the higher the melting and boiling point. Aluminum oxide will have higher melting and boiling point than magnesium oxide because Al3+ ions having