Group 7

• What group of the periodic table do halogens belong to?

  Group 7
• What are halogens primarily composed of?

  Non-metals
• What is the electron configuration of fluorine?

  1s2 2s2 2p5
• What color is chlorine gas?

  Pale green
• What is the state of bromine at room temperature?

  Browny orange liquid
• What is the state of iodine at room temperature?

  Gray solid
• How do boiling points change as you go down the group of halogens?

  Boiling points increase down the group
• Why do boiling points increase down the group of halogens?

  Molecules and atomic sizes increase, enhancing forces
• What happens to electronegativity as you go down the group of halogens?

  Electronegativity decreases
• Why does electronegativity decrease down the group of halogens?

  Atoms get larger, increasing distance and shielding
• What is the fundamental rule of displacement reactions among halogens?

  • More reactive halogens displace less reactive halides
  • Reactivity decreases down group seven
• What is formed when chlorine displaces bromide ions?

  Bromine and chloride ions
• What color indicates the formation of bromine in a displacement reaction?

  Orange solution
• What color indicates the formation of iodine in a displacement reaction?

  Brown solution
• What happens when bromine reacts with bromide ions?

  No reaction occurs
• What is bleach made from?

  Chlorine and sodium hydroxide
• What type of reaction produces bleach?

  Disproportionation reaction
• What is the oxidation state of chlorine in bleach?

  +1 and -1
• What is the primary use of chlorine in water treatment?

  To kill bacteria and pathogens
• What happens to chlorinated water when exposed to sunlight?

  It decomposes, reducing effectiveness
• What are the advantages of chlorinating water?

  Destroys microorganisms and reduces algae growth
• What are the disadvantages of chlorinating water?

  Can be toxic and irritate respiratory systems
• What is a reducing agent?

  An element that loses electrons
• Why are halide ions good reducing agents?

  They lose electrons more readily
• What are the tests for halide ions with sulfuric acid and silver nitrate?

  • Sulfuric acid: Reduction products vary by halide
  • Silver nitrate: Forms precipitates indicating halide presence
• What is the oxidation state of sulfur in concentrated sulfuric acid?

  +6
• What is produced when chloride ions react with concentrated sulfuric acid?

  Sodium hydrogen sulfate and hydrogen chloride
• What is the significance of the oxidation states in the reaction with sulfuric acid?

  Indicates reduction and oxidation processes
• Why is the reduction product of sulfuric acid important in this context?

  It helps identify the oxidation states of sulfur.
• What is the oxidation state of sulfur in sodium hydrogen sulfate?

  +6
• What happens when chloride ions react with concentrated sulfuric acid?

  They produce hydrogen chloride and sodium hydrogen sulfate.
• What is produced when sodium chloride reacts with sulfuric acid?

  Hydrogen chloride and sodium hydrogen sulfate
• What is the significance of the white misty fumes produced in the reaction?

  They indicate the formation of hydrogen chloride gas.
• How do bromide ions differ from chloride ions in their reaction with sulfuric acid?

  Bromide ions can reduce sulfur further to sulfur dioxide.
• What is produced when bromide ions react with sulfuric acid?

  Sulfur dioxide and bromine gas.
• What color vapor indicates the production of bromine in the reaction?

  Orange vapor
• What do iodide ions produce when they react with sulfuric acid?

  Solid sulfur and hydrogen sulfide gas.
• Why is it important to balance half equations in redox reactions?

  To ensure conservation of mass and charge.
• What is the smell associated with hydrogen sulfide gas?

  It smells like rotten eggs.
• What is the purpose of adding nitric acid before silver nitrate in halide tests?

  To remove other anions that could interfere.