Periodicity

Question 1

Describe sodium + water

Answer 1

1. Melts
2. Moves on surface of water
3. Fizzes
4. Gets smaller until all reacts
5. May burn with yellow/orange flame

Question 2

Sodium + water equation

Answer 2

2Na + 2H2O -> 2NaOH + H2

Question 3

Describe magnesium + water

Answer 3

1. Cold water : no visible reaction

2. Steam : burns with white flame to form white powder

Question 4

Magnesium + water equation

Answer 4

Mg + H2O -> MgO + H2

Question 5

Describe sodium + oxygen

Answer 5

Burns with yellow/orange flame

Question 6

Sodium + oxygen equation

Answer 6

4Na + O2 -> 2Na2O

Question 7

Describe magnesium + oxygen

Answer 7

Burns with bright white flame

Question 8

Magnesium + oxygen equation

Answer 8

2Mg + O2 -> 2MgO

Question 9

Describe aluminium + oxygen

Answer 9

Burns with white flame

Question 10

Aluminium + oxygen equation

Answer 10

2Al + 3O2 -> 2Al2O3

Question 11

Describe silicon + oxygen

Answer 11

Burns with white flame

Question 12

Silicon + oxygen equation

Answer 12

Si + O2 -> SiO2

Question 13

Describe phosphorus + oxygen

Answer 13

Burns with bright white flame

Question 14

Phosphorus + oxygen equation

Answer 14

P4 + 5O2 -> P4O10

Question 15

Describe sulfur + oxygen

Answer 15

Burns with blue flame

Question 16

Sulfur + oxygen equation

Answer 16

S + O2 -> SO2

Question 17

Nature and Structure of Sodium Oxide

Answer 17

Basic, Ionic

Question 18

Nature and Structure of Magnesium Oxide

Answer 18

Sparingly soluble -> Basic, Ionic (Higher melting point than Na2O as Mg2+ ions are smaller and higher charged than Na+)

Question 19

Nature and Structure of Aluminium Oxide

Answer 19

Insoluble due to very high lattice enthalpy, Ionic (not as high a melting point as expected due to some covalent character due to polarising nature of Al3+ ions)

Question 20

Nature and Structure of Silicon Oxide

Answer 20

Insoluble due to lattice of atoms linked by string covalent bonds, Giant covalent

Question 21

Nature and Structure of Phosphorus Oxide

Answer 21

Acidic, Reacts violently, Simple molecular

Question 22

Nature and Structure of Sulfur Dioxide

Answer 22

Acidic, Dissolves, Simple molecular, Gas

Question 23

Nature and Structure of Sulfur Trioxide

Answer 23

Acidic, Reacts violently, Simple molecular, Gas

Question 24

Acid-Base property of Na2O

Answer 24

Basic

Na2O + 2H+ -> 2Na+ + H2O

Question 25

Acid-Base property of MgO

Answer 25

Basic

MgO + 2H+ -> Mg2+ + H2O

Question 26

Acid-Base property of Al2O3

Answer 26

Amphoteric
Al2O3 + 6H+ -> 2Al3+ + 3H2O
Al2O3 + 2OH- + 3H2O -> 2Al(OH)4-

Question 27

Acid-Base property of SiO2

Answer 27

Acidic
SiO2 + 2OH- -> SiO3(2-) + H2O
must be hot, conc. NaOH

Question 28

Acid-Base property of P4O10

Answer 28

Acidic

P4O10 + 12OH- -> 4PO4(3-) + 6H2O

Question 29

Acid-Base property of SO2

Answer 29

Acidic

SO2 + 2OH- -> SO3(2-) + H2O

Question 30

Acid-Base property of SO3

Answer 30

Acidic

SO3 + 2OH- -> SO4(2-) + H2O