C1.4 (Frac. distillation and Chromatography) Flashcards
1
Q
What is the definition of miscible
A
Substances that dissolve completely
2
Q
What liquid do you collect first during Frac.Disti
A
The one with the lowest boiling point
3
Q
What is a fractioning Column
A
Tall glass column filled with glass beads
4
Q
What is the difference between top and bottom of fractionating column
A
Top is cooler than bottom
5
Q
What are the reasons for fractional distillation
A
- Collecting imiscible liquids
- Hard to collect liquids of similar boiling points
6
Q
Give a step by step rundown of Frac Dist
A
- Mixture heated and liquid evaporates
- Vapour moves up fractionating column
- Lower boiling point evaporates easier
- Vapour hits column and cool into liquid
- Moves up column and condenses in cooling jacket
- collected in a beaker
7
Q
Why does Chromotagraphy work
A
because compounds in a mixture dissolve better than others
8
Q
Chromotagraphy step by step
A
- Use Capillary tube to dab a spot of solution on a pencil line near the bottom of a beaker
- Placed at bottom of a solvent
- The solvent soaks up paper
- The more soluble they are the more they move up paper
9
Q
What can deduce from one spot on chromatography paper
A
A pure substance
