Halogens

Question 1

Boiling point

Answer 1

Increases down group

As diatomic ionic radius gets bigger and London forces increase

Question 2

Reactions with gr1 and 2

Answer 2

Most vig= caesium and francium and fluorine
Least= beryllium and iodine
Redox = halogen is [O]

Question 3

Displacement

Answer 3

More reactive can displace a less reactive
Indicated by colour change
After adding halogen to metal halide mix, add an organic solvent as halogens dissolve better in organics.
Iodine= purple
Bromine=orange
Chlorine=pale yellow

Question 4

Redox

Answer 4

Gas to solid at RTP

oxidising power decreases down group as ionic radius increases

DISPROORTIONATION!

Question 5

Chlorine

Answer 5

Ob’s= misty fumes
Products= HCl

Question 6

Bromide

Answer 6

Ob’s= misty fumes (HBr)
Brown fumes (Br2)
Colourless gas with choking smell (SO2)

Question 7

Iodide

Answer 7

Misty fumes= HI
Purple and gas with choking= I2
Yellow solid= S
Colourless gas with rotten egg smell= H2S

Question 8

Test for halides

Answer 8

Add nitric acid (removes anions)
Add silver nitrate ( observe colours)
Add dilute ammonia (observe precips)
Add conc. ammonia (observe precips)

Question 9

Results of test for halides

Answer 9

Silver nitrate= Cl= white Br= Cream I= yellow
Dilute ammonia= Cl= dissolves others stay
Conc. ammonia= Cl dissolves Br=dissolves I= unaffected