Period 3

Question 1

Equation for sodium and cold water + observation

Answer 1

2Na (s) + 2H20 (l) —> 2NaOH (aq) + H2 (g)

Floats and moves on water, fizzes

Question 2

Equation for sodium and oxygen + observation

Answer 2

4Na (s) + O2 (g) —> 2Na2O (s)
a yellow flame + produces a white solid

Question 3

Equation for Mg and oxygen + observation

Answer 3

2Mg (s) + O2 (g) —> 2MgO (s)
White flame and white powder produced

Question 4

Equation for Al and oxygen + observation

Answer 4

4Al (s) + 3O2 (g) —> 2Al2O3 (s)
White flame and white powder

Question 5

Equation for Si and oxygen + observation

Answer 5

Si (s) + O2 (g) —> SiO2 (s)
White flame and white powder

Question 6

Equation for Phosphorus and oxygen + observation

Answer 6

P4 (s) + 5O2 (g) —> P4O10 (s)
Very bright white flame and white powder

Question 7

Equation for Sulfur and oxygen + observation

Answer 7

S (s) + O2 (g) —> SO2 (g)
blue flame and acidic choking gas

Question 8

How is sodium stored and why

Answer 8

Under oil and phosphorus under water to stop elements coming into contact and reacting with air

Question 9

How could you experimentally prove that compounds contain ions

Answer 9

Melt the solids and show they conduct electricity

Question 10

Equation for P4O10 and water and pH + structure

Answer 10

P4O10 (s) + 6H20 (I) -> 4H3PO4 (aq)
pH 0
Structure: simple molecular

Question 11

Equation for SO2 and SO3 with water and pHs

Answer 11

SO2 (g) + H20 (I) -> H2SO3 (aq) ph 3
SO3 (g) + H20 (I) -> H2SO4 (aq) ph 0

Question 12

Equation for Na2O (s) and water and pH

Answer 12

Na2O (s) + H20 (I) -> 2NaOH
pH 14

Question 13

Equation for MgO and water and pH

Answer 13

MgO (s) + H20 (I) -> Mg(OH)2 (s) pH 10

Question 14

What are the pH’s of Al2O3 and SiO2 and why

Answer 14

pH 7 - neutral
- because they do not dissolve in water

Question 15

Describe behaviour of ionic metal oxides vs non metal covalent oxides

Answer 15

Ionic metal oxides - basic behaviour
Non metal covalent - acidic behaviour

Question 16

Equation for SiO2 and NaOH

Answer 16

2NaOH (I) + SiO2 (s) -> Na2SiO3 (aq) + H20

Question 17

What’s the equation for MgO and phosphoric acid (H3PO4)

Answer 17

3MgO + 2H3PO4 —> Mg3(PO4)2 + 3H20

Question 18

Equation for reaction of sulfur trioxide and potassium hydroxide

Answer 18

SO3 + KOH —> KHSO4

Question 19

Equation for Mg and steam + observation

Answer 19

Mg + H20 —> MgO + H2
White flame and white powder produced

Question 20

Equation for Mg and water + observation

Answer 20

Mg + 2H2O —> Mg(OH)2 + H2
Very slow reaction

Question 21

What’s silicons structure (Si)

Answer 21

Giant covalent

Question 22

What’s phosphorus structure (P4)

Answer 22

Simple molecular

Question 23

What’s Sulfur’s structure (S8)

Answer 23

Simple molecular

Question 24

What’s chlorine structure (Cl2)

Answer 24

Simple molecular

Question 25

Equation for P4O10 and base

Answer 25

P4O10 + 12OH- —> 4PO4(3-) + 6H2O

Question 26

What’s the structure of SO2 and SO3

Answer 26

Simple molecular

Question 27

Equation for SO2 with base

Answer 27

SO2 + 2OH- —> SO3(2-) + H20

Question 28

Equation for Na2O (s) and acid

Answer 28

Na2O + 2H+ —> 2Na + H20

Question 29

What’s the structure of SiO2

Answer 29

Giant covalent

Question 30

Equation for Al2O3 and acid

Answer 30

Al2O3 + 6H+ —> 2Al3+ + 3H20

Question 31

Equation for Al2O3 and base

Answer 31

Al2O3 + 2 OH- + 7H2O —> 2[Al(H20)2(OH)4]-
(Amphoteric)