The halogens

Cards (16)

Appearance of fluorine at RTP
Pale yellow gas
Appearance of chlorine at RTP
Yellow-green gas
Appearance of bromine at RTP
Red-brown liquid
Appearance of iodine at RTP
Grey solid
What is the trend in volatility in the halogens
Decreases down the group
Why does the volatility decrease down the group?
The increasing strength of instantaneous dipole - induced dipole bonds
Colours of halogens in water
Chlorine - Colourless
Bromine - Yellow/Orange
Iodine - Brown
Colours of halogens in hexane
Chlorine - Pale green
Bromine - Orange
Iodine - Violet
Oxidising agent - A substance when its reduced oxidises another substance
What's the trend in reactivity of halogens?
Decreases down the group
Why do halogens decrease in reactivity down the group?
The atomic radii is larger so the outer electrons are further from the positive nucleus
The outer electrons are shielded, making it harder for larger atoms to attract the electron needed to form an ion
Bromine displaced - turns orange
Iodine displaced - turns brown
Test for halide ions  
Test tube of sample
Add nitric acid
Add silver nitrate solution
Results of halide test
Chlorine - white precipitate
Bromine - Cream precipitate
Iodine - yellow precipitate
Addition of ammonia solution to halide test
Silver chloride - Fully dissolves
Silver bromide - Partially dissolves
Silver iodide - Insoluble
Why use nitric acid when testing for halide ions? 
To prevent any false positive results from carbonate ions precipitating out with silver ions