Group 7

• fluorine appearance 


  Yellow gas
• Chlorine appearance 


  Green gas
• Bromine appearance 


  Brown liquid, very easily forms orange vapour
• Iodine appearance 


  Grey crystalline solid- very easily forms purple vapour
• Atomic radius down group 7

  increases as there is more shells
• Electronegativity down group 7

  Decreases as atoms get bigger. There is weak attraction between nucleus and two electron in a covalent bond and there is more shielding
• Melting and boiling points

  Increases as there are bigger molecules. so more van der waals between molecules. so higher melting and boiling point between molecules
• Ionisation energy down group 7

  decrease as atoms get bigger So more shielding so weaker attraction between nucleus and outer electron in shell
• Reaction of chlorine with water

  It forms chloric acid- HClO
• Equations of reactions of chlorine with water

  Cl2 + H2O= HClO + HCl

  2Cl2 + 2H2O = 4HCl + O2 ( sunlight reaction)
• Disproportion reaction

  a type of redox reaction where the oxidation state of some atoms of the same element increase and others decrease
• Chlorine uses

  Chlorine is added in swimming pools because the chloric acid produced in the reaction kills bacteria. chloric acid is also present in bleach.
• Reaction if Cl with water

  • Reversible reactions
  • dispropotionation reaction
• Reaction of Cl with water and NaOH

  Naclo + h2o = HClO + NaOH

  Cl2 + 2NaOH = Naclo + Nacl + H2O
• Symbol equation for the reaction between chlorine and sodium bromide

  Cl2 + 2NaBr = 2NaCl + Br2
• Write an ionic equation for the reaction Between chloride and sodium bromide

  Cl2 + 2Br- = 2Cl- + Br2
• Symbol equation for the reaction between sodium chloride and sulphuric acid

  Nacl (s) + H2SO4(I) = NaHSO4(s) + HCl (g)
• Write a symbol equation for the reaction between hydrogen bromide and sulphuric acid

  HBr + H2SO4 = SO2 + 2H2O + Br2
• Symbol equation for the reaction between sodium bromide and sulphuric acid to produce bromine

  2H2SO4 + 2NaBr = Na2SO4 + SO2 +Br2 + 2H2O
• Symbol equation For the reaction between hydrogen iodide and sulphuric acid to produce H2S

  8HI + H2SO4 (l) = H2S (g) + 4H2O (l) + 4I2 (s)
• Symbol equation for the reaction between hydrogen iodide and Sulphuric acid to produce sulphur

  6HI + H2SO4 = 3I2 + S + 4H2O
• Symbol equation for the reaction between hydrogen iodide and sulphuric acid to produce sulphur dioxide

  2HI + H2SO4 = I2 + SO2 + 2H2O
• Symbol equation for the reaction between silver nitrate and sodium chloride

  AgNO3 + Nacl = AgCl + NaNO3
• Ionic equation for the reaction between silver nitrate and sodium chloride

  Ag+ (aq) + Cl- (aq) = AgCl (s)
• Ionic equation for the reaction between bromine and potassium iodide

  Br2 + 2I- = 2Br- + I2
• Equation for the reaction between chlorine and water 


  Cl2 + H20 = HClO + HCl

  • Reversible reaction
• equation for the reaction between chlorine and water in sunlight

  2Cl2 (g) + 2H2O (l) = 4HCl (aq) + O2 (g)
• Equation for the reaction between sodium chlorate and water

  NaClO + H2O = NaOH (aq) + HClO (aq)
• Equation for the reaction between chlorine and sodium hydroxide

  Cl2 + NaOH = NaClO + NaCl + H2O
• Reducing about of halide ions

  1. Iodide
  2. bromide
  3. chloride
• Explaination why iodide ion is the best reducing agent

  • Weaker attraction between outer electron and nucleus
  • ionic radius increase
  • more shielding
  • distance is getting bigger between outer electrons and nucleus
• Oxidising agent 


  Halogens
• Reducing agent 


  Halides
• Chloride ions reaction:

  • Acid + Base
• HCl ( hydrogen chloride) produce

  White misty fumes
• bromide ion reaction

  • Acid + Base
  • Redox for SO2
  • Redox for Br2
• Observation for HBr - Bromide ion test 


  White misty fume
• Observation for SO2 in bromide ions

  Chocking gas
• observation for Br2 for bromide ion

  Orange fume
• iodide ions reaction

  • Acid + Base
  • rest are all redox