Drying Gases

• Concentrated sulfuric acid


  • most gases, including chlorine and hydrogen chloride can be collected
  • gases that react with sulfuric acid cannot be collected (e.g. ammonia)

  
• Quicklime (calcium oxide)


  • Quick lime can be used for neutral gases such as ammonia, but not acidic gases
  • excluding gases that react with quicklime (e.g. hydrogen chloride)

  
• Fused Calcium Chloride


  • Fused Calcium Chloride can be used for neutral gases
  • used for collecting hydrogen, nitrogen and carbon dioxide
  • cannot be used to collect gases that react with calcium chloride (e.g. ammonia)