C2 - Miscible or Immiscible Liquids Flashcards
What does immiscible/insoluble mean?
Two or more liquids that do not mix together
What does miscible/soluble mean?
Two or more liquids that do mix together
How are two immiscible liquids separated from one and other?
They are mixed together, then separated in a separating funnel. A tap is then used to drain the bottom liquid from the top
How would miscible liquids such as Nitrogen and Oxygen (in the atmosphere) be separated?
These types of liquids would be separated using fractional distillation.
The air would be cooled so that it forms a liquid.
Heat would then be applied to the boiling point of nitrogen.
Nitrogen would then evaporate as it has reached its boiling point at the top of the column, leaving oxygen at the bottom which can then be piped as ‘liquid oxygen’.
What is Chromatography?
A technique for the separation of a mixture by passing it in solution through a medium in which the components move at different rates.
How does chromatography work? (On small scale factor)
In paper chromatography, samples are place near the bottom of a sheet of chromatography paper just below a small pencil line.
The solvent (i.e water) soaks up the paper when it is dipped
The solvent MUST NOT reach higher than the pencil line
When left the different components are carried by the solvent up the paper at different speeds so they are separated.
How do you tell if a substance is pure in chromatography?
If only one spot of color is present on the paper
How do you tell if a substance is not pure?
More than one spot will be present on the paper
What is the RF value?
The retention factor - The distance the compound has risen divided by the distance the solvent has risen
This value will alwasy be between 0 and 1
