experimental chemistry

• • measuring cylinder (nearest 0.5 cm³)
  • burette (nearest 0.05 cm³)
  • pipette (fixed volumes, 10.0 cm³/25.0 cm³)
  • gas syringe (for gases, up to 100 cm³)
• displacement of water:

  • insoluble in water (e.g. hydrogen)
  • slightly soluble in water (e.g. carbon dioxide, oxygen)
• downward delivery of gas:

  • soluble in water (e.g. chlorine)
  • very soluble in water (e.g. hydrogen chloride, sulfur dioxide)
  • denser than air
• upward delivery of gas:

  • very soluble
  • less dense than air (e.g. ammonia)
• filtration: separate insoluble solid from liquid
• evaporation to dryness: obtain soluble solid by heating solution until all of the solvent boils off
• crystallisation: obtain soluble solid by allowing a hot saturated solution to cool
• simple distillation: separate solvent from solute (e.g. water from salt)
• magnet: separate magnetic solid from non-magnetic solid
• fractional distillation: separate miscible liquid with different boiling points
• chromatography: separate mixture of substances which have different solubilities
• concentrated sulfuric acid: most gases, including chlorine and hydrogen chloride

  • not suitable for gases that react with sulfirc acid (e.g. ammonia)
• quicklime (calcium oxide): ammonia

  • must be freshly heated before use
  • not suitable for gases that react with calcium oxide (e.g. carbon dioxide)
• fused calcium chloride: hydrogen, oxygen, carbon dioxide

  • must be freshly heated before use
  • not suitable for gases that react with calcium chloride (e.g. ammonia)
• sieving: separating solids with different particle size
• sublimation: separate a substance that changes from the solid to gaseous state directly
• separating funnel: separate immiscible liquids
• parallel error: error when our eye is not placed at the same level as the meniscus when taking readings from a measuring instrument
• function of drying agent: removes moist or water content from a substance