Period 3 oxides 3.2.4

Question 1

When period 3 oxides burn in oxygen what do they form?

Answer 1

white solid oxides

Question 2

What is the reaction between sodium and oxygen?

Answer 2

4Na + O2 => 2Na2O

Question 3

What is the reaction between magnesium and oxygen ?

Answer 3

2Mg + 1/2O2 => MgO

Question 4

What is the reaction between aluminium and oxygen?

Answer 4

4Al + 3O2 => 2Al2O3

Question 5

What is the reaction between silicon and oxygen ?

Answer 5

Si + O2 => SiO2

Question 6

What is the reaction between phosphorus and oxygen ?

Answer 6

P4 + 5O2 => P4O10

Question 7

How does sodium react with water?

Answer 7

• Vigorously
• Forms a ball and fizzing
• Hydrogen gas is produced

Question 8

What is the reaction of sodium and water ?

Answer 8

2Na + 2H2O => 2NaOH + H2

Question 9

What is the reaction between sodium oxide and water?

Answer 9

Na2O + H2O => 2NaOH

Question 10

what’s the ph of sodium oxide?

Answer 10

14

Question 11

What’s the reaction between sodium oxide and acid?

Answer 11

Na2O + 2H+ => 2Na+ + H20

Question 12

what happens when magnesium reacts with water?

Answer 12

• reacts slowly
• forms a weak alkaline solution of magnesium hydroxide ( Mg(OH)2)
• this is a weak alkaline solution as magnesium hydroxide is sparingly soluble

Question 13

what’s the reaction of magnesium and water?

Answer 13

Mg + 2H2O => Mg(OH) + H2

Question 14

What’s the reaction between magnesium and steam?

Answer 14

Mg + H2O => MgO (s) + H2

Question 15

why is magnesium oxide less soluble than sodium oxide?

Answer 15

magnesium oxide has higher lattice enthalpy

Question 16

what’s the reaction between magnesium oxide and water?

Answer 16

Mgo + H2O => Mg(OH)2

Question 17

what’s the ph of magnesium oxide ?

Answer 17

10

Question 18

what’s the reaction between magnesium oxide and acid?

Answer 18

MgO + 2H+ => Mg2+ + H2O

Question 19

why is aluminium oxide insoluble?

Answer 19

very high lattice enthalpy

Question 20

what name is given to aluminium oxide

Answer 20

amphoteric

Question 21

what’s the reaction between aluminium oxide and acid?

Answer 21

Al2O3 + 6H+ => 2Al3+ + 3H2O

Question 22

what’s the reaction between aluminium oxide and alkali?

Answer 22

Al2O3 + 6H+ => 2Al3+ + 3H2O

Question 23

what’s the reaction between aluminium oxide and hydrochloric acid?

Answer 23

Al2O3 + 6HCl => 2AlCl3 + 3H2O

Question 24

what’s the reaction between aluminium oxide and sodium hydroxide?

Answer 24

Al2O3 + 2NaOH + 3H2O => 2NaAl(OH)4

Question 25

why is silicon (IV) oxide insoluble (SiO2) ?

Answer 25

lattice of atoms linked by strong covalent bonds that would have to be broken

Question 26

what’s the reaction between silicon oxide and an alkali?

Answer 26

SiO2 + 2OH- => SiO3- +H2O

Question 27

what’s the reaction between phosphorus oxide and water?

Answer 27

P4O10 + 6H2O => 4H3PO4

Question 28

what is the ph of phosphorus oxide and why?

Answer 28

1.5
H2O molecules attach the S+ P atoms leading to the release of H+ ions from the water molecules

Question 29

what’s the reaction between phosphorus oxide and alkali?

Answer 29

P4O10 + 12OH- => 4PO43- +6H2O

Question 30

What happens when Sulfur oxide (SO2) reacts with water?

Answer 30

it dissolves

Question 31

what’s the rection between sulfur oxide and water?

Answer 31

SO2 + H2O => H2SO3

Question 32

what’s the ph of sulfur oxide and why?

Answer 32

1.3
H2O molecules attach to the S+ S atoms , leading to the release of H+ ions from the water molecules

Question 33

what’s the reaction between sulfur oxide and alkali?

Answer 33

SO2 + 2OH- => SO3 2- + H2O

Question 34

What happens when Sulfur (VI) oxide (SO3) reacts with water?

Answer 34

reacts violently

Question 35

what’s the reaction between SO3 and water?

Answer 35

SO3 + H2O => H2SO4

Question 36

what’s the ph of SO3 and why?

Answer 36

0

H2O molecules attach to the S+ S atoms , leading to the release of H+ ions from the water molecules

Question 37

what’s the reaction between sulfur trioxide and hydroxide ?

Answer 37

SO3 + 2OH- => SO4 2- +H2O

Question 38

what’s the trend in PH in period 3 oxides?

Answer 38

• Acidity increased from left to right
• Ranging from strongly basic oxides on the left to strongly acidic on the right
• with an amphoteric oxide in the middle

Question 39

Why do Na2O , MgO and Al2O3 have high melting points?

Answer 39

• form giant ionic lattices
• giant ionic lattices have lots of strong attractive forces which require a lot of energy to break the bonds

Question 40

why does MgO have a higher melting point than Na2O?

Answer 40

It forms 2+ ions and Na forms +1 ions.
The 2+ ions are attracted more strongly to the oxygen

Question 41

Why does Al2O3 have a lower melting point than MgO?

Answer 41

• Al3+ ions distort the electron cloud of oxygen.
  This means that there’s some covalent character as well as ionic interactions.
  Less energy is required to break the bonds

Question 42

Why does SiO2 have a higher melting point than the non metal oxides (P4O10 and SO2)?

Answer 42

• Forms a giant covalent structure.
  Many strong covalent bonds which require lots of energy to break.

Question 43

Why does P4O10 and SO4 have lower melting points than SiO2?

Answer 43

• They form simple molecular structure.
  Weaker intermolecular forced so less energy required to break the bonds

Question 44

why does the reaction of sodium oxide reacting with water forms a solution that is more alkaline?

Answer 44

Sodium has a higher solubility

Question 45

what’s the equation for sulfur reacting with oxygen ?

Answer 45

S + O2 => SO2

Question 46

what would you see if you react sulfur with oxygen ?

Answer 46

Brown fumes