10.3 - Reactions of halide ions

• Negative ions of Halogens are known as halide ions which are good reducing agents
• The reducing power increases down the group as electrons are easier to lose from larger ions due to shielding and larger atomic radius
• The greater the reducing power, the longer the reaction as the halide is powerful enough to reduce more species
• Sodium chloride (Solid)

  • Steamy fumes of hydrogen chloride are seen
  • Solid produce is sodium hydrogensulfate
  • Similar reactions with sodium fluoride but the fluoride ion is a weaker reducing agent that chloride

  
• Sodium bromide (Solid) 

  • Steamy fumes of hydrogen bromide and brown fumed of Bromine
  • Colourless sulfur dioxide is also formed  

  
• Sodium iodide (Solid)

  • Steamy fumes of hydrogen iodide, black solid of Iodine
  • Bad egg smell of hydrogen sulfide gas is present
  • Yellow solod sulfur may also be seen
  • Colourless sulfur dioxide is also evolved