3.2.4 Properties of period 3 elements and their oxides

Question 1

Write an equation for sodiums reaction with water

Answer 1

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

Question 2

Describe the reaction of sodium with water

Answer 2

• This reaction is vigorous with cold water
• The solution you get is highly basic
• Effervescence

Question 3

Write an equation for magnesiums reaction with water

Answer 3

Mg(s) + 2H2O(l) → Mg(OH)2(aq) + H2(g)

Question 4

Describe the reaction of magnesium with water

Answer 4

• This reaction is slow with cold water

Question 5

Write an equation for magnesiums reaction with steam

Answer 5

Mg(s) + H2O(g) → MgO(s) + H2(g)

Question 6

Describe the reaction of magnesium with steam

Answer 6

• This is a vigorous reaction and makes the Mg burn with a white light

Question 7

Write an equation for the reaction between sodium and oxygen

Answer 7

4Na(s) + O2(g) → 2Na2O(s)

Question 8

Write an equation for the reaction between magnesium and oxygen

Answer 8

2Mg(s) + O2(g) → 2MgO(s)

Question 9

Write an equation for the reaction between aluminium and oxygen

Answer 9

4Al(s) + 3O2(g) → 2Al2O3(s)

Question 10

Write an equation for the reaction between silicon and oxygen

Answer 10

Si(s) + O2(g) → SiO2(s)

Question 11

Write an equation for the reaction between phosphorus and oxygen

Answer 11

P4(s) + 5O2(g) → P4O10(s)

Question 12

Write an equation for the formation of sulphur dioxide

Answer 12

S(s) + O2(g) → SO2(g)

Question 13

Write an equation for the formation of sodium trioxide

Answer 13

2SO2(g) + O2(g) → 2SO3(g)

Question 14

What catalyst is required for the formation of sodium trioxide ?

Answer 14

A vanadium pentoxide catalyst (V2O5)

Question 15

What colour flame does sodium produce ?

Answer 15

Yellow

Question 16

What colour flame does magnesium produce ?

Answer 16

Brilliant white

Question 17

What colour flame does phosphorous produce ?

Answer 17

Brilliant white

Question 18

What colour flame does sulphur dioxide produce ?

Answer 18

Blue

Question 19

What period 3 oxides are ionic ?

Answer 19

• MgO
• Na2O
• Al2O3

Question 20

What type of bonding is found in SiO2 ?

Answer 20

It is a giant covalent structure

Question 21

What period 3 oxides have simple molecular bonding ?

Answer 21

• P4O10
• SO3

Question 22

What period 3 oxide has the highest melting point ?

Answer 22

MgO

Question 23

Which period 3 oxide has the lowest melting point ?

Answer 23

SO3 as it has very weak Van Der Waals

Question 24

Is sodium hydroxide an acid or base and what is its PH ?

Answer 24

Sodium hydroxide is a strong base, so the pH of this solution will be between 12 and 14

Question 25

Is magnesium hydroxide an acid or base and what is its PH ?

Answer 25

Magnesium hydroxide is a weak base, so the pH of this solution will be between 9 and 10

Question 26

Is Al2O3 an acid or base ?

Answer 26

It is amphoteric so can act as an acid or base

Question 27

Is phosphoric acid an acid or base and what is its PH ?

Answer 27

It is an acid and will have a solution of this will have a pH of ~ 0-2

Question 28

Is sulforous acid an acid or base and what is its PH ?

Answer 28

It is an acid and will have a pH between 0 and 2

Question 29

Is sulphuric acid an acid or base and what is its PH ?

Answer 29

It is one of the strongest acids, and will have a pH of ~ 0-2

Question 30

The oxides of period 3 elements become more ___ across the period

Answer 30

Acidic

Question 31

Why is sodium more reactive with water than Mg ?

Answer 31

As it takes less energy to lose one electron than 2