Group 7

• electronegativity increases/decreases down the group.

  decreases, F is most electronegative
• Halides are best reducing agents down the group
• oxidising ability of halogens is decreasing down the group
• Test for group 2 metals

  Barium chloride and dilute sodium hydroxide
• Test for ammonium ions

  sodium hydroxide and heat, red litmus paper turns blue if positive
• test for halide ions

  nitric acid, acidifies silver nitrate and ammonia solution
• testing for carbonate ions

  dilute HCl and sodium carbonate and limewater
• testing for sulfate ions

  add dilute HCl and aqueous barium chloride