C2.1.7 - Purification And Checking Purity Flashcards Preview

C1 - C3 > C2.1.7 - Purification And Checking Purity > Flashcards

Flashcards in C2.1.7 - Purification And Checking Purity Deck (8):
1

What can you use to tell if a substance is pure?

Thin-layer chromatography or paper chromatography

2

Which is better at checking pure substances - paper or thin-layer chromatography?

Thin-layer chromatography

3

What are the advantages of using thin-layer chromatography over paper chromatography for checking pure substances?

It is quicker
It is more sensitive, so a smaller substance can be used
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 by using gas chromatography

4

Wha do you need to know about the substances in order to use the correct separation method?

The properties of the substances

5

How do you separate insoluble substances?

Dissolving followed by filtration

6

How do you separate solutions?

Crystallisation to obtain the solute
Simple distillation to obtain the solvent

7

How do you separate two or more substances in the liquid state?

Fractional distillation

8

How do you separate coloured soluble solutions?

You use paper chromatography or thin-layer chromatography