C2.1.7 - Purification And Checking Purity Flashcards
What can you use to tell if a substance is pure?
Thin-layer chromatography or paper chromatography
What is better at checking pure substances between the two?
Thin Layer Chromatography
What are the advantages of using thin-layer chromatography over paper chromatography for checking pure substances?
It is quicker
I5 is more sensitive
There is a larger range of chemical phases to choose from
You can also scrape an individual spot for further analysis from a thin layer chromatogram using gas chromatography
What do you need to know about the substances in order to use the correct separation method?
The properties of the substances
How do you separate insoluble substances?
Dissolving followed by filtration
How do you separate solutions?
Crystallisation to obtain the solute
Simple distillation to obtain the solvent
How do you separate two or more substances in the liquid state?
Fractional distillation
How do you separate coloured soluble solitons?
Paper Chromatography or Thin-Layer Chromatography