Paper Chromatography

SEPARATION
TECHNIQUES:
PAPER
CHROMATOGRAPHY

12 January 2023

LESSON OBJECTIVES

1 Describe how paper chromatography separates and purifies

mixtures

2 Interpret paper chromatograms including comparison with

‘known’ samples and the use of Rf values

3 Explain the need to use locating agents in the

chromatography of colourless compounds

RECAP

1

HOW MUCH DO YOU

REMEMBER KNOW ABOUT

CHROMATOGRAPHY?

Open Ended

State a purpose of chromatography.

Multiple Choice

chromatography separates the mixture of dyes on the basis of their ----------------------------

• density

• solubility

• gravity

• boiling point

Multiple Choice

A pure substance shows ------------------ spot on chromatogram

• 0

• 1

• 2

• 3

Multiple Choice

Which of the dyes contains an insoluble color?

• 6

• 5

• 4

• 3

Multiple Choice

Which of the following mixture/s is/are separated by chromatography?

• Pigments from natural colours

• Colours in a dye

• Colours of flowers extracts

• All the above

CONDITIONS

STARTING LINE

SOLVENT LINE

TYPE OF SOLVENT

1

2

3

Multiple Choice

What was the mistake made for this chromatogram?

• Starting line drawn with pen

• Solvent line above the spots

• Dyes are insoluble in solvent

• Too much solvent

Multiple Choice

What was the mistake made for this chromatogram?

• Starting line drawn with pen

• Solvent line above the spots

• Dyes are insoluble in solvent

• Too much solvent

CONSTRUCT
UNDERSTANDING

2

SETUP OF CHROMATOGRAPHY

ACTUALLY…

HOW DO WE

KNOW WHICH

IS THE MOST

SOLUBLE?

—SOMEONE FAMOUS

“The retention factor, Rf value, of a

substance is a measure of its

solubility in the sovent .”

ACTUALLY…

APPLICATION

3

Fill in the Blanks

Multiple Choice

The R_f value  for the blue component is 

• 0.3

• 0.7

• 10

• 3

Multiple Choice

The R_f value  for the red component is 

• 0.3

• 0.7

• 10

• 7

WHAT IF THE
DYE/INK
COMPONENTS IS
COLOURLESS?

LOCATING AGENTS

Forms coloured spots with

substances on chromatogram