Group 7

• Fluorine Colour


  Yellow gas
• Chlorine Colour


  Green gas
• Bromine Colour


  Orange/Brown liquid
• Iodine Colour


  Grey solid
• Boiling Points as you go down the group

  Increase because the strength of the Van der Waals increases with the atomic radius
• Electronegativity as you go down the group


  Decreases as distance from the nucleus and shielding increase
• Reducing power of ions as you go down the group


  Increases as the distance from the nucleus and shielding increase making it easier for an electron to be lost
• Fluoride with silver nitrate


  No precipitate
• Chloride with silver nitrate


  White Precipitate
• Bromide with silver nitrate


  Cream Precipitate
• Iodide with silver nitrate


  Yellow Precipitate
• Silver Chloride with ammonia


  white precipitate dissolves in dilute ammonia
• Silver bromide with ammonia


  cream precipitate dissolves in concentrated ammonia
• Silver iodide with ammonia


  yellow precipitate insoluble in concentrated ammonia
• Oxidising power down the group


  Decreases down the group, as there is an increase in shielding, weakening the attraction to outer electrons.
• KCl + H2SO4 =

  HCl + KHSO4 Acid-Base reaction
• KBr + H2SO4 =


  Br2. +. SO2 Redox
• KI + H2SO4 =

  I2 + H2S(rotten egg smell), purple burst REDOX
• Cl2 + H2O <=> in the dark


  HClO(chloric(1) acid) + HCl Kills microbs ^
• 2Cl2 + 2H2O = in sunlight


  4HCl + O2. (No HClO!)
• What is used to clean swimming pool water?

  NaClO (salt of HClO) The ph of swimming pools must not drop to acidic, or Cl2 will come out of solution