Unit 3.5.2 - Periodicity Flashcards
What is the equation for the reaction between aluminium oxide and H₂SO₄?
Al₂O₃(s) + 3H₂SO₄(aq) → Al(SO₄)₃(aq) + 3H₂O(l)
Why is sodium more reactive than magnesium?
Because it takes less energy to lose one electron than it does tow, so more energy (usually heat) is needed for magnesium to react
Why can aluminium oxide be classed amphoteric?
They neutralise acids or bases
What is the equation for the reaction between phosphorus oxide and water?
P₄O₁₀(s) + 6H₂O(l) → 4H₃PO₄(aq)
Does silicon dioxide react with water?
No it is insoluble
What are period 3 elements usually oxidised too? However what is the expectation to this?
Their highest oxidation state, sulphur as it only goes to a +4 state
How fast is the reaction with aluminium and air?
Slow
What is the equation for the reaction between magnesium and oxygen?
Mg(s) + ¹/₂O₂(g) → MgO(s)
What is the equation for the reaction between silicon and oxygen?
Si(s) + O₂(g) → SiO₂(s)
Which of the period 3 oxides dissolve in water to form hydroxides?
Na and Mg
What is the equation for the equation between phosphorus oxide and NaOH?
P₄O₁₀(s) + 12NaOH(aq) → 4Na₃PO₄(aq) + 6H₂O(l)
Why do phosphorus oxide and sulphur dioxide have relatively low melting points?
They form simple molecular structures and so there is only weak intermolecular forces between the molecules which are easy to overcome and so take less energy meaning they have quite a low melting point
What can aluminium oxide be classed as?
Amphoteric
What is the equation for the reaction between sulphur trioxide and water?
SO₃(l) + H₂O(l) → H₂SO₄(aq
What is the equation for the equation between sulphur trioxide and NaOH?
SO₃(g) + 2NaOH(aq) → Na₂SO₄(aq) + H₂O(l)
What colour flame is produced when you burn sodium in air?
Yellow
What do period 3 elements form when they react with oxygen?
Element oxides
How does magnesium react with water?
It reacts very slowly with cold water, you can’t see any reaction is taking place, H₂ gas and Mg(OH)₂ is produced
What is the equation for the reaction between sodium oxide and water?
Na₂O(s) + H₂O(l) → 2NaOH(aq)
Why can silicon, phosphorus and sulphur oxides be classed as acidic?
They can neutralise bases
What is the equation for the reaction between sulphur dioxide and water?
SO₂(g) + H₂O(l) → H₂SO₃(aq)
What ions does sodium produce when it reacts with water?
Na⁺
How fast is the reaction between sulphur and air?
It burns steadily
Why do the metal oxides in period 3 have high melting points?
There are strong forces of attraction between the oppositvely charged ions which means it takes a lot of heat energy to break the bonds and melt them
What test can you do do identify the period 3 element?
The flame test
Is sodium or magnesium more reactive with water?
Sodium
What colour flame is produced when you burn magnesium in air?
Brilliant white