C16 - Organic synthesis Flashcards
What does a basic set of quickfit apparatus include?
Round bottom flask
Receiver
Screw-tap adaptor
Condenser
Still head
What apparatus do you need to heat under reflux?
Round-bottom/pear-shaped flask
Condenser
Rubber tubing
Stand and clamp
Heat source
Heating under reflux diagram
How do you set up a practical where you have to heat under reflux?
1) Clamp pear shaped flask by its neck
2) Add reaction mixture and anti-bumping granules
3) Add thin layer of grease onto joint of condenser
4) Place condenser into flask (upright) and rotate it to provide good seal
5) Rubber tubing connects connects condenser inlet (bottom) to tap and condenser outlet (top) sink
6) Heat source under flask
What are anti-bumping granules used for?
Allow liquid to boil smoothly
Prevent large bubbles forming at the bottom of the glassware making it vibrate
What does heating under reflux allow?
Enables liquid to be continually boiled, preventing volatile components from escaping
What apparatus do you need to distil?
Round-bottom/pear-shaped flask
Condenser
Rubber tubing
Stand and clamp
Heat source
Screw-cap adaptor
Still head
Thermometer
Distillation diagram
How do you set up a practical where you have to distil?
1) Flask clamped by its neck
2) Still head (T shaped) connected to flask
3) Two joints of still head fitted to screw cap adaptor and condenser
4) Second clamp placed around receiver adaptor which is attached to condenser (horizontal)
5) Rubber tubing connects connects condenser inlet (bottom) to tap and condenser outlet (top) sink
6) Heat source
7) Flask to collect distillate
Which liquid drips into collecting flask first?
Liquid with lowest boiling point and it is the most volatile
What are the two layers formed when preparing samples of organic liquids?
Organic layer
Aqueous layer
How can you identify the organic layer?
-Using densities
-Add water, the layer that gets larger is the aqueous layer
How do you use a separating funnel?
1) Ensure tap of the funnel is closed
2) Pour the mixture of liquids into the separating funnel and place a stopper in the top
3) Invert to mix contents
4) Add some water to identify aqueous layer
5) Place conical flask under separating funnel and remove the stopper
6) Slowly open the tap until the whole layer has left the funnel
7) Repeat with different conical flask
How do you remove acidic impurities
Add aqueous sodium carbonate in the separating funnel and then invert
Tap needs to be opened slowly whilst holding separating funnel upside down to release CO2 produced
Remove aqueous sodium carbonate layer
How do you dry the organic product?
Add a drying agent - inorganic anhydrous salt
