Period 3 oxides Flashcards
What type of structure does Na₂O have?
Ionic
What type of structure does MgO have?
Ionic
What type of structure does Al₂O₃ have?
Ionic
What type of structure does SiO₂ have?
Giant covalent
What type of structure does P₄O₁₀ have?
Simple molecular
What type of structure does SO₃ have?
Simple molecular
Why do Na₂O, MgO and Al₂O₃ all have high boiling points?
They form giant ionic lattices so there are strong forces of attraction between each ion and it takes a lot of heat energy to overcome the bonds and melt them
Why does MgO have a higher boiling point than Na₂O?
Magnesium forms 2+ ions which attract the O²⁻ ions more strongly than the +1 sodium ions in Na₂O
Why is the boiling point of Al₂O₃ lower than you’d expect?
The 3+ ions distort the oxygen’s electron cloud making the bonds partially covalent
Why does SiO₂ have a higher boiling point than other non-metal oxides?
It has a giant macromolecular structure
Strong covalent bonds hold the structure together so lots of energy is needed to break the bonds and the melting temperature is high
Why do P₄O₁₀ and SO₃ have relatively low boiling points?
They are simple molecular and the molecules are attracted to each other by weak intermolecular forces which take little energy to overcome
What is the equation for Na₂O in water?
Na₂O(s) + H2O(l) -> 2NaOH(aq)
What is the equation for MgO in water?
MgO(s) + H2O(l) -> Mg(OH)₂(aq)
What is the equation for phosphorus oxide and water?
P₄O₁₀(s) + 6H₂O(l) -> 4H₃PO₄(aq)
What acid is formed when phosphorus oxide and water react?
Phosphoric acid
What is the equation for sulfur dioxide and water?
SO₂(g) + H₂O(l) -> H₂SO₃(aq)
What acid is formed when sulfur dioxide and water react?
sulphuric (IV) acid
What is the equation for the dissociation of phosphoric acid in water?
H₃PO₄(aq) -> 3H+(aq) + PO₄³⁻(aq)
What is the equation for the dissociation of sulfuric (IV) acid in water?
H₂SO₃(aq) -> 2H+(aq) + SO₃²⁻(aq)
What is the equation for sulfur trioxide and water?
SO₃(g) + H2O(l) -> H₂SO₄(aq)
What acid is formed when sulfur trioxide reacts with water?
Sulfuric (VI) acid
What is the equation for the dissociation of sulfuric (VI) acid in water?
H₂SO₄(aq) -> 2H+(aq) + SO₄²⁻(aq)
What does amphoteric mean?
It can act as an acid or a base
What is an example of an amphoteric compound?
Al₂O₃
What is formed when you react an acid and a base?
Salt and water
Are sodium and magnesium oxides basic or acidic? What do they neutralise?
Basic
Acids
Are silicon, phosphorus and sulfur oxides acidic or basic? What do they neutralise?
Acidic
Bases
Are aluminium oxides acidic or basic? What do they neutralise?
Both - they are amphoteric
they neutralise both acids and bases
