Group 7 Halogens And Redox

Question 1

What is oxidising power

Answer 1

The ability to remove an electron

Question 2

Oxidising power trend

Answer 2

Cl2> Br2 > I2

Question 3

The reaction table of halogens for oxidising power

Answer 3

Question 4

The equation of Cl2 and KCl

Answer 4

There is no reaction

Question 5

The reaction between Br2 and KCl

Answer 5

There is no reaction

Question 6

The reaction of KCl and I2

Answer 6

There is no reaction

Question 7

Why is there no reaction of KCl with the halides

Answer 7

As Br2 and I2 are not a good oxidising powers. They have a bigger atomic radius than Cl2 which mean it cannot remove an electron from the potassium as easily as Cl2 can.

Question 8

The reaction of KBr and Cl2

Answer 8

Question 9

The ionic equation of KBr and Cl2

Answer 9

Question 10

What is the observation we see with the reaction of KBr and Cl2

Answer 10

Orange solution

Question 11

The reaction of KI and Cl2 including ionic

Answer 11

Question 12

The observation of KI and Cl2

Answer 12

Brown solution

Question 13

The reaction of KI and Br2 including ionic

Answer 13

Question 14

The observation of KI and Br2

Answer 14

Brown solution

Question 15

Formation of bleach reaction

Answer 15

Question 16

What is bleach, chemical formula

Answer 16

NaClO

Question 17

What is bleach used for

Answer 17

Cleaning agent

Question 18

What is the reaction of bleach called and why

Answer 18

Disproportionation as the chlorine is being oxidised and reduced at the same time

Question 19

The reaction of Cl2 and H20

Answer 19

Question 20

The reaction of Cl2 and H20 in UV light

Answer 20

Question 21

Is Cl2 and H20 reaction a disproportionation reaction

Answer 21

Yes

Question 22

Why is chlorine used for water treatment even though it is toxic

Answer 22

The benefits outweighs the risks

Question 23

Reducing power of halides

Answer 23

I2>Br2>Cl2

Question 24

What is reducing power

Answer 24

The ability to lose an electron

Question 25

Why is Iodine a good reducing agent

Answer 25

It can easily lose its electron because there is a weaker force of attraction between nucleus and outer electron compared to chlorine Iodine can easily be oxidised (lose and electron) so it acts as a reducing agent. Something oxidised is a reducing agent and something reduced is an oxidising agent

Question 26

Reaction of NaCl and H2SO4

Answer 26

Question 27

Reaction of NaF with H2SO4

Answer 27

Question 28

Observation of NaCl and H2SO4

Answer 28

Misty white fumes (HCl produced)

Question 29

Observation of NaF and H2SO4

Answer 29

Misty white fumes (HF produced)

Question 30

Reaction of NaBr and H2SO4 the two equations

Answer 30

Question 31

Observation of NaBr and H2SO4

Answer 31

``` Misty white fumes (HBr produced) Brown fumes (Br2 gas produced) ```

Question 32

Reaction of NaI and H2SO4 four reactions

Answer 32

4. 8HI + H2SO4 —-> 4I2 +H2S +4H2O

Question 33

Observation of NaI and H2SO4

Answer 33

Misty white fumes (HI produced) Black solid/ purple fumes (I2 produced) Bad egg smell, toxic (H2S produced) Yellow solid (sulfur produced)

Question 34

Test for halides

Answer 34

Add HNO3 which is acid that removes unwanted ions such as Carbonate ions Add Silver Nitrate (AgNO3) Chloride - white ppt Bromide - cream ppt Iodide - yellow ppt

Question 35

Ionic equation for test of halides

Answer 35

Question 36

Ionic equation for halide Cl2

Answer 36

Question 37

Ionic equation for halide test Br2

Answer 37

Question 38

Ionic equation for halide test Br2

Answer 38

Question 39

Trend of atomic radius in group 7

Answer 39

Increases More shells More shielding So bigger atoms

Question 40

Trend of electronegativity in group 7

Answer 40

Decreases More shells More shielding Weaker attraction b/w nucleus and two electrons in covalent bond

Question 41

Trend of boiling/melting group 7

Answer 41

``` Increases More electrons Bigger atomic radius More vdw Higher melting and boiling between molecules as halogens are SCM ```

Question 42

Ionisation energy trend of group 7

Answer 42

Decreases More shells More shielding Weaker forces of attraction b/w nucleus and electron in outer shell

Question 43

Displacement in aqueous solutions table of halides in an organic layer

Answer 43

Question 44

Oxidation state of H2

Answer 44

+1 unless joined to a metal - becomes -1

Question 45

Oxidation state of O2

Answer 45

-2 always unless joined to H2O2 (hydrogen peroxide) - becomes -1

Question 46

Table of reactions for reducing power along with equations

Answer 46