Chapter 16 Flashcards
What does a standard set of Quickfit apparatus contain?
1 Round-bottom or pear-shaped flask
2 Receiver
3 Screw-tap adapter
4 Condenser
5 Still head
What equipment is needed for heating under reflux?
Round-bottom or pear-shaped flask
Condenser
Rubber tubing
Stand and clamp
Heat source (bunsen burner or heating mantle)
What is the purpose of anti-bumping granules?
They are used to ensure that the contents are boiled smoothly
At which ends of a condenser does water flow in and out?
When a condenser is in an upright position, water always enters at the bottom and leaves at the top
When horizontal, water always enters at the lowest point and leaves at the highest point
How is distillation used in purification?
Distillation is a common method used to separate a pure liquid from its impurities
What equipment are needed for distillation?
Round-bottom or pear-shaped flask
Condenser
Rubber tubing
Heat source
Stand and clamp
Screw-cap adapter
Receiver adapter
Still head
Thermometer
How is an organic layer distinguished from an aqueous layer when purifying organic products?
To identify the organic layer, water is added to the mixture. The layer that gets bigger must be the aqueous layer
What method is used to remove an organic layer from an aqueous layer?
A separating funnel is used to separate the two layers.
Place the liquid within a separating funnel and invert several times.
The layer with the largest density would settle at the bottom and this layer can then be run off
How are acid impurities removed in organic liquids?
By adding aqueous sodium carbonate and shaking the mixture
How to remove excess water from an organic liquid?
By adding an anhydrous salt (e.g. anhydrous calcium chloride or anhydrous calcium sulfate)
What final step is done in purification if organic liquids have boiling points that are close together?
The organic liquid is redistilled. Using a thermometer, only heat until you reach the stated boiling point of one of the liquids
Overall, what are the 4 steps used in purification of organic liquids?
- Use a separating funnel
- Add sodium carbonate
- Add an anhydrous salt
- Redistill
Reagents and conditions to turn an alkane into a haloalkane:
Halogen (e.g. Br2)
UV light
Reagents and conditions to turn a haloalkane into an alcohol:
Heat under reflux with aqueous sodium hydroxide
Reagents and conditions to turn an alkene into a alkane:
Hydrogen
Nickel catalyst