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Flashcards in The Halogens Deck (20)
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1

What happens down the halogen group in terms of boiling point?

It increases

2

Explain the trend in boiling point down the halogen group

Id-Id or London forces increase so more energy is needed to overcome them

3

What happens down the halogen group in terms of reactivity with halide ions?

Decreases

4

Explain the trend in reactivity down the halogen group with halide ions

The added electron is further from the nucleus and it shielded by more electrons in inner shells so the electrostatic attraction decreases and so reactivity decreases

5

What are displacement reactions in terms of halogens?

Reactions in which a more reactive halogen will oxidise and displace a less reactive halogen from its salt

6

What can halogen solutions be added to, to produce displacement reactions?

NaCl
NaBr
NaI

7

What is the colour of chlorine in water?

Pale green

8

What is the colour of bromine in water?

Orange

9

What is the colour of iodine in water?

Brown

10

What is the colour of chlorine in cyclohexane?

Pale-green

11

What is the colour of bromine in cyclohexane?

Orange

12

What is the colour of idoine in cyclohexane?

Purple

13

What happens to show that a redox reaction has taken place with halogens reacting with halide ions?

A colour change

14

What is usually also added to the solution of halogen and sodium halide?

Usually shaken with cyclohexane to distinguish between bromine and iodine

15

Which halogen in the most reactive?

Chlorine

16

What is the colour change of halogens determined by?

The halogen in the solution - the most reactive halogen oxides the halide ions and so becomes the halide ions so the colour is determined by the halogen

17

The equation of chlorine and water in water treatment

Cl2 + H2O ----------> HClO + HCl

18

Equation of chlorine and sodium hydroxide and what it forms (specific ion)

Cl2 + 2NaOH ----------> NaCl + NaClO + H2O
Forms bleach (ClO-)

19

What conditions are needed for when chlorine makes bleach

Reacts with cold, dilute aqueous NaOH

20

Name 2 negatives for the chlorination of water

Cl's toxicity means care has to be taken
Can react with organic matter to form chlorinated hydrocarbons which may be carcinogenic