Chromatography Experiment: Investigating Inks or Pigments in Black Ink

The video tutorial explains chromatography, a method to separate pigments in black ink using a solvent and stationary phase. It covers the concept of retention factor (RF) value, the setup of a chromatography experiment using filter paper and water, and the analysis of chromatogram results. The tutorial also discusses how different solvents affect the separation of pigments and concludes with a note on pure compounds producing a single spot.

What is the role of the mobile phase in chromatography?

• To remain stationary and hold the test substance

• To dissolve the test substance and move it along the stationary phase

• To provide a surface for the test substance to adhere to

• To change the color of the test substance

Why is filter paper used in the chromatography experiment instead of ink?

• Because filter paper is more colorful

• Because ink is not available

• Because ink is too expensive

• Because ink might dissolve in water and affect the results

How is the RF value calculated in chromatography?

• By multiplying the distance moved by the substance by the distance moved by the solvent

• By dividing the distance moved by the solvent by the distance moved by the substance

• By dividing the distance moved by the substance by the distance moved by the solvent

• By adding the distances moved by the substance and the solvent

What can be concluded if a pigment does not appear in a chromatogram with a specific solvent?

• The pigment has a very high RF value

• The pigment is not present in the mixture

• The pigment is not soluble in that solvent

• The pigment is too small to be seen

What does a single spot on a chromatogram indicate about a compound?

• The compound is highly soluble

• The compound has multiple pigments

• The compound is impure

• The compound is pure