Period 3 Elements

Question 1

How does sodium react with water?

Answer 1

-Reacts vigorously with cold water
-Forms a molten ball on surface
-Fizzes
-Produces H2 gas

Question 2

What is the equation for sodium reacting with water?

Answer 2

2Na(s)+2H2O(l)–>2NaOH(aq)+H2(g)

Question 3

How does magnesium react with water?

Answer 3

-Reacts very slowly with cold water
-Forms a weak alkaline solution

Question 4

What is the equation for magnesium reacting with water?

Answer 4

Mg(s)+2H2O(l)–>Mg(OH)2(aq)+H2(g)

Question 5

How does magnesium react with steam?

Answer 5

-Reacts much faster than with cold water

Question 6

What is the equation for when magnesium reacts with steam?

Answer 6

Mg(s)+H2O(g)–>MgO(s)+H2(g)

Question 7

What is the general equation for a period 3 element reacting with oxygen?

Answer 7

Element+Oxygen–>Oxide

Question 8

What colour flame does sodium produce?

Answer 8

-Yellow

Question 9

What colour flame does magnesium produce?

Answer 9

-Bright white

Question 10

What colour flame does aluminium produce?

Answer 10

-N/A

Question 11

What colour flame does silicon produce?

Answer 11

-N/A

Question 12

What colour flame does phosphorus produce?

Answer 12

-Bright white

Question 13

What colour flame does sulfur produce?

Answer 13

-Blue

Question 14

How do Na and Mg react with air?

Answer 14

-Vigorously

Question 15

How do Al and Si react with air?

Answer 15

-Slowly

Question 16

How does P react with air?

Answer 16

-Spontaneously combusts

Question 17

How does S react with air?

Answer 17

-Burns steadily

Question 18

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

Answer 18

-Giant ionic lattices
-Strong forces of attraction between each ion

Question 19

Why does MgO have a higher melting point than Al2O3?

Answer 19

-Al2O3 is slightly covalent
-Electronegativity between Al and O isn’t as large as between Mg and O

Question 20

Why does SiO2 have a higher melting point than other non-metal oxides?

Answer 20

-It has a macromolecular structure

Question 21

Explain why SiO3 and P4O10 have low melting points?

Answer 21

-Simple covalent molecules
-Dipole-dipole and van der waals forces which are weak

Question 22

Why does sodium oxide make a more alkaline solution than magnesium oxide when reacting with water?

Answer 22

-NaOH is more soluble in water
-More hydroxide ions form

Question 23

What is the equation for sodium oxide reacting with water?

Answer 23

Na2O(s)+H2O(l)–> 2NaOH(aq)

Question 24

What is the equation for magnesium oxide reacting with water?

Answer 24

MgO(s)+H2O(l)–>Mg(OH)2(aq)

Question 25

What is the equation for phosphorus oxide reacting with water? What acid is formed?

Answer 25

P4O10(s)+6H2O(l)–>4H3PO4(aq)
-Acid=phosphoric(V) acid

Question 26

What is the equation for sulfur dioxide reacting with water? What acid is produced?

Answer 26

SO2(g)+H2O(l)–>H2SO3(aq)
-Acid=sulfurous acid/sulfuric(IV) acid