Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A-Level Chemistry > Group 7 > Flashcards

Group 7 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

What are the characteristics of fluorine?

A

Colour- pale yellow
Physical state- gas
highly reactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the characteristics of chlorine?

A

Colour- green
Physical state - gas
poisonous in high concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the characteristics of bromine?

A

Colour- red-brown
Physical state- liquid
produces dense brown/orange poisonous fumes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the characteristics of iodine?

A

Colour- grey
Physical state-solid
produces purple gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the trend of boiling points down the group?

A

The boiling points increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why do the boiling points increase down the group?

A

Down the group, the molecules are larger
There are more electrons
Therefore, there are stronger van der Waals forces
More energy is required to break the forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the trend of electronegativity up the group?

A

The electronegativity increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why does the electronegativity increase up the group?

A

The atomic radius decreases
there is less shielding
there is a stronger force of attraction on the electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is electronegativity?

A

The relative tendency of an atom in a molecule to attract electrons in a covalent bond to itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is fluorine the most electronegative element?

A

It is the smallest atom with the most need to fill its shell

it has the least number of electrons and shells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when a halogen reacts with a halide in a solution?

A

A halogen will displace a halide from the solution if the halide is below the halogen in the periodic table

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the trend of oxidising strength down the group?

A

The oxidising strength decreases down the group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens when potassium chloride reacts with chlorine?

A

No reaction

Remains green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens when potassium chloride reacts with bromine?

A

No reaction

Remains orange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens when potassium chloride reacts with iodine?

A

No reaction

Remains brown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens when potassium bromide reacts with chlorine?

A

Orange solution formed

Chlorine has been displaced by bromine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens when potassium bromide reacts with bromine?

A

No reaction

Remains orange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens when potassium bromide reacts with iodine?

A

No reaction

Remains brown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens when potassium iodide reacts with chlorine?

A

Brown solution formed

Chlorine displaced by iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens when potassium iodide reacts with bromine?

A

Brown solution formed

Bromine displaced by iodine

21
Q

What happens when potassium iodide reacts with iodine?

A

No reaction

22
Q

What is the trend of the reducing power of the halides down the group?

A

The reducing power increases down the group

23
Q

Why does the reducing power increase down the group?

A
  • the ions get bigger down the group
  • the further away the outer electrons are from the nucleus
  • there is more shielding
  • weaker force of attraction
24
Q

What happens when the reducing power increases down the group?

A

The greater the reducing power
the greater the reactivity
the faster the reduction reactions take place

25
Q

What happens when fluoride reacts with concentrated sulfuric acid?

A

NaF(s) + H2SO4(aq) → NaHSO4(s) + HF(g)

26
Q

What happens when chloride reacts with concentrated sulfuric acid?

A

NaCl(s) + H2SO4(aq) → NaHSO4(s) + HCl(g)

27
Q

Why are the reactions between fluoride and chloride with concentrated sulfuric acid not redox reactions?

A

HF and HCl aren’t strong enough reducing agents to reduce the sulfuric acid
The oxidation states of the halide and sulfur remain the same

28
Q

What happens when bromide reacts with concentrated sulfuric acid?

A

NaBr(s) + H2SO4(aq) → NaHSO4(s) + HBr(g)

2HBr(aq) + H2SO4(aq) → Br2(g) + SO2(g) + 2H2O(l)

29
Q

What happens when iodide reacts with concentrated sulfuric acid?

A

NaI(s) + H2SO4(aq) → NaHSO4(s) + HI(g)
2HI(g) + H2SO4(aq) → I2(s) + SO2(g) + 2H2O(l)
6HI(g) + SO2(aq) → 3I2(s) + H2S(g) + 2H2O(l)

30
Q

What observations can be made when bromide reacts with concentrated sulfuric acid?

A

steamy fumes of HBr are produced
Red fumes of Br2
colourless, acidic gas, SO2

31
Q

What observations can be made when iodide reacts with concentrated sulfuric acid?

A 
steamy fumes of HI are produced
black solid and purple fumes of I2
colourless acidic gas, SO2
yellow solid, sulfur
toxic, rotten egg smell, H2S
32
Q

What observations can be made when iodide reacts with concentrated sulfuric acid?

A 
steamy fumes of HI are produced
black solid and purple fumes of I2
colourless acidic gas, SO2
yellow solid, sulfur
toxic, rotten egg smell, H2S
33
Q

How would you test for halides using silver nitrate

A

Add nitric acid to the solution to remove ions which may give a false positive result
Add a few drops of silver nitrate solution
A precipitate is formed
The colour of the precipitate will determine the halide present

34
Q

What is the colour of the precipitate when silver nitrate is used to test chlorides?

A

White precipitate

35
Q

What is the colour of the precipitate when silver nitrate is used to test bromides?

A

Cream precipitate

36
Q

What is the colour of the precipitate when silver nitrate is used to test iodides?

A

Yellow precipitate

37
Q

What is the trend of solubility of silver halides in ammonia?

A

The solubility decreases down the group

38
Q

What observations would be made when ammonia is added to silver chloride?

A

White precipitate

Silver chloride dissolves in dilute ammonia

39
Q

What observations would be made when ammonia is added to silver bromide?

A

Cream precipitate

Silver bromide dissolves in concentrated ammonia

40
Q

What observations would be made when ammonia is added to silver iodide?

A

Yellow precipitate

Insoluble in both dilute and concentrated ammonia

41
Q

Why is chlorine used in water?

A

It kills bacteria

42
Q

What happens when chlorine reacts with water?

A

It undergoes disproportionation

43
Q

What is disproportionation?

A

A reaction where an is element simultaneously oxidised and reduced

44
Q

What happens when chlorine reacts with water?

A

Cl2(g) + H2O(l) → 2H+(aq) + Cl-(aq) + ClO(aq)

45
Q

What happens when chlorine reacts with water in sunlight?

A

2Cl2(g) + 2H2O(l) → 4H+(aq) + 4Cl-(aq) + O2(g)

46
Q

What are the disadvantages of using chlorine for water treatment?

A
  • chlorine gas is harmful
  • liquid chlorine causes severe burns
  • chlorine reacts with organic compounds in water forming chlorinated hydrocarbons which are carcinogenic
47
Q

Why is chlorine still used in water treatment?

A

The benefits to health of water treatment by chlorine outweighs its toxic effects

48
Q

What happens chlorine reacts with cold, dilute aqueous NaOH?

A

2NaOH(aq) + Cl2(g) → NaClO(aq) + NaCl(aq) + H2O(l)

49
Q

What is sodium chlorate(NaClO) used for?

A

bleach

A-Level Chemistry (30 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions