8.2 The Halogens Flashcards
What is the group 7 boiling trend?
As you go down the group:
1) More electrons
2) Stronger London forces
3) More energy is required to break the intermolecular forces
4) The boiling point increases
What colour does a chlorine solution have in water?
Pale green
What colour does a bromine solution have in water?
Orange
What colour does an iodine solution have in water?
Brown
What colour does a chlorine solution have in cyclohexane?
Pale green
What colour does a bromine solution have in cyclohexane?
Orange
What colour does an iodine solution have in cyclohexane?
Violet
What is the trend in reactivity of group 7 down the group?
Reactivity decreases down the group
Why does the reactivity of group 7 decrease down the group?
As you go down the group:
1) atomic radius increases
2) more inner shells so shielding increases
3) less nuclear attraction to gain an electron
4) reactivity decreases
What is a disproportionation reaction?
A redox reaction in which the same element is both oxidised and reduced
How do you test for halides?
You add silver nitrate to the compound
What precipitate do chlorine ions form?
A white precipitate
What precipitate do bromine ions form?
A cream precipitate
What precipitate do iodine ions form?
A yellow precipitate
Is the chloride precipitate soluble in dilute or concentrated NH3 ?
Dilute
