1. More on the Halogens

2. Objectives Be able to... Recall how to test for the presence of halides using silver nitrate Explain the storage and transport risks associated Describe a range of uses of the halogens

3. Specification... Where this comes from...

4. Reactions with Silver Nitrate Can you suggest a use for the silver halides? Which silver halide precipitate is formed most quickly? How is AgNO 3 used to test for halide ions? Halide Colour of precipitate Formula of precipitate Solubility in ammonia Fluorideno ppt. soluble Chloride whiteAgCl soluble BromidecreamAgBr partially soluble IodideyellowAgI insoluble

8. Uses of Fluorine Fluorine, often via hydrogen fluoride, is used to manufacture many other products. Fluorine and its compounds Processing uranium nuclear fuel Fluoridation of water Toothpaste, to prevent tooth decay fluorine-containing polymers, e.g. Teflon

9. Uses of Chlorine pesticides and weed killer Drinking water treatment Chlorine and its compounds HCl Bleach to kill bacteria and to make paper white antiseptics and disinfectants Chlorinated carbon compounds, e.g. solvents and plastics (PVC)

10. Uses of Bromine and Iodine Iodine and its compounds Bromine and its compounds medicines antiseptic Leaded petrol (being phased out) agriculture photography Animal feed supplements

11. Transport issues Use storylines books