Organic Synthesis and Analysis Flashcards
1
Q
What is heating under reflux and what does it prevent
A
- Continuous cycle of evaporation/boiling and condensing
- Prevents the loss of compounds via evaporation
2
Q
What is simple distillation used for?
A
- Separating miscible liquids
- That have a large difference in boiling points
3
Q
What is fractional distillation used for?
A
- Separating miscible liquids
- With similar boiling points
4
Q
What is steam distillation used for?
A
- Separate insoluble liquids from reaction mixture
- When the substance decomposes when heated therefore reduces thermal decomposition with steam distillation
5
Q
What is distillation under pressure/vacuum distillation used for?
A
- Reduces thermal decomposition
6
Q
How can two immiscible liquids be separated?
A
- With a separating funnel
- Decant (pour slowly)
7
Q
What is filtration used for and how can it be made faster?
A
- Vacuum filtration
- Removes an insoluble solid from liquid
8
Q
How can a pure solid be obtained using recrystallisation.
A
- Dissolve the solid in the minimum volume of hot solvent
- Filter hot if required to remove insoluble impurities
- Cool to recrystallize
- Filter, wash and dry to constant mass
- Measure the melting point and compare with known value
9
Q
In chromatography what is the mobile phase and what is the stationary phase?
A
- Mobile > gas/liquid
- Stationary > the paper
10
Q
A
