Halogens

Question 1

What are the group 7 elements?

Answer 1

Chlorine, Florine Iodine and Bromine

~they exist as diatomic

Question 2

What are the different types of halite ions?

Answer 2

Bromide
Chloride
Iodide

• they exist as single ions with a charge -1

Question 3

Reactivity series of halogens?

Answer 3

1. 2.
   3.

*More reactive halogen displaces weaker halogens

Question 4

What colour is produced when chlorine and KBR reacts? Why does it change this color? Give equation ionic/symbol:

Answer 4

Orange solution - Because bromine is the product in the reaction

{ Cl2 + 2KBR -> Br2 + 2KCL }

ionic: { Cl2 + Br-
- -> Br2 + 2Cl-}

Question 5

What happens when chlorine and potassium iodine?

Answer 5

Brown solution

Question 6

What happens when bromine reacts with potassium iodide?

Answer 6

Brown Solution

Question 7

What is the formation of bleach?

Answer 7

2NaOH + Cl2 –> NaClO + NaCl +

H20

Question 8

What is bleach used for?

Answer 8

Cleaning

Question 9

What is a disproportionation reaction?

Answer 9

Is a reaction were same thing is oxidized and reduced

Question 10

What is the word equation for chlorine and water?

Answer 10

Cl2 + H20 ⇌ HClO (chloric 1 acid) + HCl

Question 11

Why is chlorine used to treat water?

Answer 11

They benefit outweighs the risk

Question 12

Why is chlorine used to treat water?

Answer 12

It kills bacteria making it clean preventing spread of disease

Question 13

What are the disadvantages of using chlorine to treat water?

Answer 13

It is toxic

Question 14

What is a reducing agent?

Answer 14

a substance that tends to bring about reduction by being oxidized and losing electrons.

Question 15

Are halides reducing agents?

True/False

Answer 15

True

Question 16

What happens when halide and sulfuric acid reacts?

Answer 16

metal halide + sulfuric acid —> metal sulfate + hydrogen halide

e.g.

NaCl + H2SO4 –> NaHSO4 + HCl

Question 17

Why is a reaction between metal halides and sulfuric acid non redox?

Answer 17

This is because there no change in oxidation states

Question 18

What is released between a reaction with sulfuric acid and metal halide?

Answer 18

Misty White Fumes

Question 19

What happens during reaction of hydrogen bromine and sulfuric acid?

Answer 19

2HBr + H2SO4 —-> Br2 + SO2 + 2H20

Question 20

Is hydrogen bromide and sulphric acid a redox reaction?

TRUE/ FALSE

Answer 20

TRUE

Question 21

What happens when you react hydrogen halide and sulfuric acid?

Answer 21

hydrogen halide + sulfuric acid —> halogen + sulfuric oxide + water

e.g.

2HI + H2SO4 —> I2 + SO2 + 2H20

Question 22

What happens when you react hydrogen halide and sulfur oxide?

Answer 22

hydrogen halide + sulfur oxide –> hydrogen halide + halogen + water

e.g.

6HI + SO2 –> H2S + 3I2 + 2H20

Question 23

How do you test for halides?

Answer 23

Add Nitric Acid (HNO3) and Silver Nitrate (AgNO3)

If present:
Chlorine - White precipitate

Iodide - Yellow Precipitate

You can conduct an ammonia (NH3) test:

Chlorine - dissolves in dilute ammonia

Bromine - dissolves in concentrated ionic ammonia

Iodine - does not dissolve in ammonia

Question 24

What is the the generic symbol equation for halide test?

Answer 24

Ag+ (+) X- —-> AgX

X = Halide

Question 25

Halogen order according to reducing power

Answer 25

1. Iodine (Largest)
2. Bromine
3. Chlorine (Weakest)

Question 26

What is the trend in boiling point as you go down group 7? Why?

Answer 26

The boiling point increases - this is because van der walls forces increase due to the increasing size and relative mass of atoms

Question 27

How does states change as you go down group 7?

Answer 27

gas at the top and solid at the bottom

Question 28

How does electronegativity change as you go down the group? Why?

Answer 28

As you go down elecronegativity decreases - This is because the larger the atom the distance between positive nucleus and bonding electrons increase know as shielding

Question 29

What is electronegativty?

Answer 29

Is the ability for an atom to attract electrons towards its’ covalent bond

Question 30

What happens with reactivity as you go down group 7?

Answer 30

Reactivity decreases