SC2c - Paper Chromatography (SHOULD BE IN CHEMISTRY )

Question 1

How is chromatography used?

Answer 1

To find which coloured compounds a mixture contains

Question 2

Why does paper chromatography work?

Answer 2

Some compounds dissolve better in a solvent than others

Question 3

What happens when the solvent moves along the strip of paper?

Answer 3

The different substances in a mixture are carried at various speeds so they are separated

Question 4

What’s the mobile phase in chromatography?

Answer 4

The solvent

Question 5

What is the stationary phase in chromatography?

Answer 5

The layer

Question 6

What is the chromatogram?

Answer 6

The paper with the separated components on it

Question 7

How do you calculate the Rf value?

Answer 7

The distance moved by the spot divided by the distance moved by the solvent

Question 8

If the Rf values of two compounds are the same what does it mean?

Answer 8

The compounds are the same

Question 9

Give the uses of paper chromatography

Answer 9

Distinguish between pure and impure substances

Identify substances by comparing patterns and calculating the Rf value

Question 10

When does the Rf value of the same substance not change?

Answer 10

If the chromatography conditions used remain the same