5.1 - Period 3 Elements Flashcards
What observations are there when sodium reacts with water?
It forms a floating molten ball that fizzes due to H₂ gas being produced.
What is the equation for sodium reacting with water?
2Na + 2H₂O —-> 2NaOH + H₂
What is the pH of the solution formed when sodium reacts with water?
12-14.
What observations are there when magnesium reacts with cold water?
There aren’t any observations as the reaction occurs very slowly.
What is the equation for magnesium reacting with cold water?
Mg + 2H₂O —-> Mg(OH)₂ + H₂
What is the pH of the solution formed when magnesium reacts with cold water?
9-10.
What is the equation when magnesium reacts with steam?
Mg + H₂O —-> MgO + H₂
What is the equation for sodium reacting with oxygen?
2Na + ½O₂ —-> Na₂O
What colour flame is there when sodium reacts with oxygen?
Yellow.
What is the equation for magnesium reacting with oxygen?
Mg + ½O₂ —-> MgO
What colour flame is there when magnesium reacts with oxygen?
Brilliant white.
What is the equation for aluminium reacting in air?
2Al + 1½O₂ —-> Al₂O₃
What is the equation for silicon reacting with oxygen?
Si + O₂ —-> SiO₂
What is the equation for phosphorus reacting with oxygen?
P₄ + 5O₂ —-> P₄O₁₀
What colour flame does phosphorus burn with?
A brilliant white flame.
What is the equation for sulphur reacting with air?
S + O₂ —-> SO₂
What colour flame does sulphur burn with?
Blue.
Which oxides form giant ionic lattices?
Na₂O, MgO and Al₂O₃
Which oxides form a macromolecular structure?
SiO₂
Which oxides form simple covalent molecules?
P₄O₁₀, SO₂ and SO₃.
What is the trend in period three oxide melting points?
The overall trend is that they decrease. However, Na₂O is lower than MgO because Mg²⁺ has a higher charge density than Na⁺.
Why does Al₂O₃ have a lower melting point than MgO?
The difference in electronegativity between Al and O and Mg and O is lower. This makes the bond partially covalent.
What is the equation for the reaction of P₄O₁₀ with water?
P₄O₁₀ + 6H₂O —-> 4H₃PO₄
What is the equation for the reaction between sulphur dioxide and water?
SO₂ + H₂O —-> H₂SO₃
Why will sodium and magnesium oxide neutralise acids?
They are basic.
What is the equation for the reaction between sodium oxide and HCl?
Na₂O + 2HCl —-> 2NaCl + H₂O
Which period three oxides will neutralise bases?
Aluminium, Silicon, Phosphorus and Sulphur Oxides.
What is the equation for the reaction of SiO₂ with NaOH?
SiO₂ + 2NaOH —-> Na₂SiO₃ + H₂O
What is the equation for the reaction of P₄O₁₀ and NaOH?
P₄O₁₀ + 12NaOH —-> 4Na₃PO₄ + 6H₂O
What is the equation for the reaction of sulphur dioxide and NaOH?
SO₂ + 2NaOH —-> Na₂SO₃ + H₂O
What is the equation for the reaction of aluminium oxide and sulphuric acid?
Al₂O₃ + 3H₂SO₄ —-> Al₂(SO₄)₃ + 3H₂O
What is the equation for the reaction of aluminium oxide with NaOH?
Al₂O₃ + 2NaOH + 3H₂O —-> 2NaAl(OH)₄
