Separating Mixtures Flashcards
1
Q
What Is fractional distillation and how does it work
A
- it separates a liquid from a mixture of liquids
- when you heat up the mixture, one of the liquids will evaporate and move up the each fractioning column, stopping on each level, eventually, the liquid with the lowest boiling point will evaporate and the process will continue until all of the liquids have been evaporated and separated
2
Q
What is simple distillation and how does it work
A
- separates a solvent from a solution
- the solution is heated until the solvent evaporates, the gas is collected and then is condensed in the cooling chamber, where it is then collected in a Beaker
3
Q
Crystallisation
A
- it separates a solute form a solvent
- produces a dry sample of the solute
- works by heating the solution up until the solvent evaporates, leaving the solute behind
4
Q
What is filtration
A
- Separates an insoluble solid from a liquid
- filter paper lets through liquid as filtrate
- the insoluble solid substance left over forms residue
5
Q
What are the two phases in chromatography
A
- stationary phase = paper (in paper chromatography it is the silica that it is coated in)
- mobile phase = the solvent
6
Q
What does it mean if the substance travels up very high in paper chromatography
A
It means that the substance has high bonding with the mobile phase (the solvent). If it does not move up that high, it means it has a higher bonding with the stationary phase.
7
Q
What are the mobile phase and stationary phase in gas chromatography and TLC
A
In gas chromatography, the
- mobile phase is the gas, which is also used as the solvent.
- stationary phase is the silica gel which coats the inside chamber
In TLC, the
- mobile phase is the solvent that the paper is suspending in
- the stationary phase is the silica gel that coats the paper
8
Q
How to calculate RF value
A
Rf = distance travelled by substance / distance travelled by solvent
