Gas Collection

• Displacement of water


  • gas must be insoluble in water (hydrogen) or slightly insoluble in water (e.g. oxygen, carbon dioxide)

  
• Downward delivery


  • gas can be soluble in water (e.g. chlorine) or very soluble in water (e.g. hydrogen chloride)
  • gas must be denser than air
• Upward Delivery


  • gas can be very soluble in water
  • gas must be less dense than air (e.g. ammonia)