2.4 Period 3 oxides Flashcards
How does sodium react with water?
Vigorously, with lots of effervescence
What is the formula for the Na + H₂O reaction?
2Na + 2H₂O = 2NaOH + H₂
How does magnesium react with water?
Very slowly, only really reacts with steam
What is the formula for the Mg + H₂O reaction?
Mg + 2H₂O = Mg(OH)₂ + H₂
What is the sodium oxide formula?
Na₂O
What is the magnesium oxide formula?
MgO
What is the aluminium oxide formula?
Al₂O₃
What is the silicon oxide formula?
SiO₂
What is the phosphorus oxide formula?
P₄O₁₀
What is the sulfur oxide formula?
SO₂ / SO₃
What is the trend in boiling point of oxides across period 3?
- Na < Mg < Al oxides giant ionic bonding so high MP
- SiO₂ is giant covalent, so high MP
- P₄H₁₀ < SO₂ < SO₃, simple covalent, so lower MP
What does sodium oxide + water =
NaOH
- Alkali
- pH 14
What does magnesium oxide + water =
Mg(OH)₂
- Alkali
- pH 9
What does aluminium oxide + water =
INSOLUBLE
What does silicon dioxide + water =
INSOLUBLE
What does phosphorus oxide + water =
H₃PO₄
- Acid
- pH -1 - +1
What does sulfur dioxide + water =
H₂SO₃
- Acid
- pH 2-3
What does sulfur trioxide + water =
H₂SO₄
- Acid
- pH -1 - +1
How does sodium oxide & magnesium oxide react with acid?
Form SALT and water (metal oxide + acid reaction)
How does aluminium oxide react with acid?
Forms SALT and water
How does aluminium oxide react with alkali?
Forms a hydroxide
What is it called when an oxide reacts with both an alkali and an acid?
Amphoteric
What is the only amphoteric oxide in period 3?
Aluminium oxide
How does silicon dioxide react with acid?
- Acts as a weak acid
Forms a SALT and water
