Practical Techniques Flashcards
Steam distilllation method?
Organic liquids that have very high BP or decompose upon heating and are insoluble in water —> STEAM DISTILLATION
Steam is passed into mixture and product vapour is distilled off with steam and condensed
- organic compound and water separated with separating funnel
ADVANTAGE: product distils at a lower temp which prevents decomposition of product if it has a high BP
How can melting point indicate purity?
MP of impure compound will be LOWER than MP of PURE compound/lower than value in data booklet
Melting range will be broader if impure
Can be measured in an electronic melting point machine OR use capillary tube strapped to thermometer immersed in heating oil (which has higher BP than sample’s MP)
- put some of sample in capillary tube + tube is heated slowly near MP
Error could occur if temp of thermometer is not same as temp in the capillary tube
