10.3- REACTIONS OF HALIDE IONS

Question 1

Can halide ions act as rerducing agents?

Answer 1

yes

Question 2

What happens in reaction where the halide ion is a reducing agent?

Answer 2

halide ions lose electrons and become halogen molecules

Question 3

What is the trend in reducing ability linked to?

Answer 3

linked to size of ions

Question 4

If the ion is larger, how does this affect how easily it loses an electron?

Answer 4

larger the ion, more easily it loses an electron

Question 5

Why can larger ions lose an electron more easily?

Answer 5

because electron lost from outer shell which is further from nucleus as ion gets larger so attraction to outer electron less

Question 6

How does reducing power changes down the halogen group?

Answer 6

reducing power increases

Question 7

What reaction reflects the reducing power of the halide ions?

Answer 7

solid sodium halides react with concentrated sulphuric acid- products different + reflect reducing power of halide ions

Question 8

What happens when drops of concentrated sulphuric acid is added to solid sodium chloride?

Answer 8

steamy fumes of hydrogen chloride is seen

Question 9

What is the solid product formed when sodium chloride and concentrated sulphuric acid react?

Answer 9

sodium hydrogensulfate

Question 10

What is the symbol equation for the reation between sodium chloride and concentrated sulphuric acid?

Answer 10

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

Question 11

When sodium chloride and concentrated sulphuric acid react, is this a redox reaction?

Answer 11

it is not a redox reaction

Question 12

When sodium chloride and concentrated sulphuric acid react, why is it not a redox reaction?

Answer 12

no oxidation state has changed

Question 13

Why does no oxidation state change?

Answer 13

chlorine is too weak a reducing agent to reduce sulphur in sulphuric acid

Question 14

What type of reactions is it when sodium chloride and concentrated sulphuric acid react?

Answer 14

acid-base reaction

Question 15

What can the sodium chloride and concentrated sulphuric acid reaction be used to prepare?

Answer 15

hydrogen chloride gas

Question 16

What was hydrogen chloride gas once called?

Answer 16

salt gas

Question 17

Where does a similar reaction to sodium chloride and concentrated sulphuric acid happen?

Answer 17

with sodium fluoride and concentrated sulphuric acid

Question 18

What dangerous product is formed when sodium fluoride and concentrated sulphuric acid react?

Answer 18

extremely dangerous gas that will etch glass

Question 19

Is the fluoride ion a weaker or stronger reducing agent in comparison to the chloride ion?

Answer 19

fluoride ion is an even weaker reducing agent than the chloride ion

Question 20

What happens when sodium bromide and concentrated sulphuric acid react? (2)

Answer 20

steamy fumes of hydrogen bromide and brown fumes of bromine

Question 21

What else is formed when sodium bromide and concentrated sulphuric acid react?

Answer 21

colourless sulphur dioxide also formed

Question 22

How many reactions occur when sodium bromide and concentrated sulphuric acid react?

Answer 22

two reactions occur

Question 23

What is first produced when sodium bromide and concentrated sulphuric acid react?

Answer 23

sodium hydrogensulfate and hydrogen bromide

Question 24

What type of reactions is it when sodium hydrogensulfate and hydrogen bromide is produced?

Answer 24

acid-base reaction

Question 25

What is the equation for when sodium hydrogensulfate and hydrogen bromide is produced from reacting sodium bromide and concentrated sulphuric acid?

Answer 25

NaBr (s) + H2SO4 (l) = NaHSO4 (s) + HBr (g)

Question 26

Why do the bromide ions reduce the sulphuric acid to sulphur oxide?

Answer 26

they are strong enough reducing agents

Question 27

What is the second reaction of sodium bromide and concentrates sulphuric acid known as?

Answer 27

redox reaction

Question 28

Are the reactions exothermic or endothermic?

Answer 28

exothermic and some of the bromine vaporises

Question 29

What do you see when sodium iodide and concentrates sulphuric acid react? (2)

Answer 29

steamy fumes of hydrogen iodide | black solid of iodine

Question 30

What can be smelt when sodium iodide and concentrates sulphuric acid react?

Answer 30

bad egg smell of hydrogen sulphide gas present

Question 31

What may also be seen when sodium iodide and concentrated sulphuric acid react?

Answer 31

yellow solid sulphur may also be seen

Question 32

What is also evolved when sodium iodide and concentrated sulphuric acid react?

Answer 32

colourless sulphur dioxide

Question 33

How many reactions take place when sodium iodide and concentrated sulphuric acid react?

Answer 33

several reactions occur

Question 34

What is produced in the acid-base reactions first when sodium iodide and concentrates sulphuric acid react?

Answer 34

hydrogen iodide

Question 35

What is the equation for when hydrogen iodide is formed when sodium iodide and concentrated sulphuric acid react?

Answer 35

NaI (s) +H2SO4 (l) = NaHSO4 (s) + HI (s)

Question 36

Is iodide ions or bromide ions better reducing agents?

Answer 36

iodide ions are better reducing agents

Question 37

As iodide ions are better reducing agents than bromide ions what do they do to sulphuric acid?

Answer 37

reduce sulphur in sulphuric acid even further

Question 38

As the sulphur in the sulphuric acid is reduced even further by the iodide ions, what does this produce?

Answer 38

sulphur dioxide, sulphur and hydrogen sulphide gas produced