Group 7

Question 1

What type of molecule are halogens?

Answer 1

diatomic molecules

Question 2

What is the appearance of fluorine at room temperature?

Answer 2

pale yellow gas

Question 3

What is the appearance of chlorine at room temperature?

Answer 3

greenish gas

Question 4

What is the appearance of bromine at room temperature?

Answer 4

red-brown liquid

Question 5

What is the appearance of iodine at room temperature?

Answer 5

black solid

Question 6

How does atomic radius change down the halogens?

Answer 6

atoms bigger
each element has extra filled main level to previous

Question 7

What is the trend in electronegativity down the halogens?

Answer 7

decreases

Question 8

Why does electronegativity decrease down the group?

Answer 8

shared electrons become further from halogen nucleus
increased shielding from inner shells

Question 9

How does melting and boiling points change down Group 7?

Answer 9

Increase

Question 10

Why does the melting and boiling point increase down Group 7?

Answer 10

atoms are larger
more electrons
stronger van der Waals forces

Question 11

How does oxidising ability change down Group 7?

Answer 11

decreases from F>Cl>Br>I

Question 12

Are halogens reduced or oxidised?

Answer 12

reduced

Question 13

What happens in a halide halogen displacement reaction?

Answer 13

Halide in compound displaced by more reactive halogen

Question 14

How does fluorine react with a fluoride ion?

Answer 14

no reaction

Question 15

How does fluorine react with a chloride ion?

Answer 15

oxidises

Question 16

How does fluorine react with a bromide ion?

Answer 16

oxidises

Question 17

How does fluorine react with an iodide ion?

Answer 17

oxidises

Question 18

How does chlorine react with a fluoride ion?

Answer 18

isn’t oxidised

Question 19

How does chlorine react with a chloride ion?

Answer 19

no reaction

Question 20

How does chlorine react with a bromide ion?

Answer 20

oxidises

Question 21

How does chlorine react with an iodide ion?

Answer 21

oxidises

Question 22

How does bromine react with a fluoride ion?

Answer 22

isn’t oxidised

Question 23

How does bromine react with a chloride ion?

Answer 23

isn’t oxidised

Question 24

How does bromine react with an iodide ion?

Answer 24

oxidises

Question 25

How does iodine react with a fluoride ion?

Answer 25

Isn’t oxidised

Question 26

How does iodine react with a chloride ion?

Answer 26

Isn’t oxidised

Question 27

How does iodine react with a bromide ion?

Answer 27

isn’t oxidised

Question 28

How does iodine react with an iodide ion?

Answer 28

no reaction

Question 29

How does bromine react with a bromide ion?

Answer 29

no reaction

Question 30

What do halide ions act as?

Answer 30

Reducing agents

Question 31

How does reducing power change down Group 7?

Answer 31

increases from F>Cl>Br>I

Question 32

How does sodium chloride react with sulfuric acid?

Answer 32

NaCl (s) + H2SO4 (l) > NaHSO4 (s) + HCl (g)

Question 33

What are the products for the reaction between sodium chloride and sulfuric acid?

Answer 33

steamy fumes of hydrogen chloride and solid sodium hydrogensulfate

Question 34

How does sodium bromide react with sulfuric acid?

Answer 34

1: NaBr (s) + H2SO4 (l) > NaHSO4 (s) + HBr (g) 2: 2H+ + 2Br- + H2SO4 (l) > SO2 (g) + 2H2O (l) + Br2 (l)

Question 35

What are the products of the reaction between sodium bromide and sulfuric acid?

Answer 35

solid sodium hydrogensulfate, steamy fumes of hydrogen bromide and colourless sulfur dioxide

Question 36

How does sodium iodide react with concentrated sulfuric acid?

Answer 36

1: Na(s) + H2SO4(l) > NaHSO4(s) + HI (g) 2: 8H+ + 8I- + H2SO4(l) > H2S(g) + 4H2O(l) + 4I2(s) 3: H2SO4(l) + 2I- + 2H+ > SO2(g) + I2(s) + 2H2O(l) 4: H2SO4(l) + 6I- + 6H+ > S(s) + 3I2(s) + 4H2O(l)

Question 37

What are the products in the reaction between sodium iodide and concentrated sulfuric acid?

Answer 37

solid hydrogensulfate, hydrogen iodide, hydrogen sulfide, sulfur, iodine, sulfur dioxide

Question 38

How are metal halides identifies through the use of silver ions?

Answer 38

1. Dilute nitric acid to halide solute to remove carbonate and hydroxide impurities 2. Few drops of silver nitrate 3. Precipitate will form

Question 39

What precipitate does chlorine form?

Answer 39

White

Question 40

What precipitate does fluorine form?

Answer 40

No precipitate

Question 41

What precipitate does bromine form?

Answer 41

Cream

Question 42

What precipitate does iodine form?

Answer 42

Pale yellow

Question 43

How can we test further with a chlorine precipitate?

Answer 43

dissolved in dilute ammonia

Question 44

How can we test further for a bromine precipitate?

Answer 44

dissolves in concentrated ammonia

Question 45

How can we test further with iodine precipitate?

Answer 45

Insoluble

Question 46

How does chlorine react with water?

Answer 46

Cl2(g) + H2O(l) <> HClO(aq) + HCl(aq)

Question 47

What is produced in the reaction between water and chlorine?

Answer 47

chloric (I) acid and hydrochloric acid

Question 48

What is chlorine used for?

Answer 48

Prevent life threatening diseases Treats water by killing bacteria/microorganisms

Question 49

What does chloric acid do?

Answer 49

Acts as oxidising agent which kills bacteria

Question 50

What alternative reaction shows how water exposed to sunlight is chlorinated?

Answer 50

NaClO(s) + H2O(l) <> Na+(aq) + OH-(aq) + HClO(aq)