Which statement describes Paper chromatography?

Which statement describes Paper chromatography?

• A. Laboratory technique used to observe the different pigments in a material
• B. A technique used to separate gases
• C. A method to observe color changes in reactions
• D. A method to observe pH

Answer: (A)

Paper chromatography separates mixtures by moving components through a stationary phase (the paper) with a moving solvent. The different pigments in a material interact differently with the paper and with the solvent, so they travel at different speeds and form separate spots. This makes it possible to observe and compare the pigments present. The description fits because it captures the main use of paper chromatography: to observe the different pigments that exist in a material, often by visualizing distinct colored spots on the paper. The other ideas don’t fit as well: separating gases is done with gas chromatography, which uses a gas phase and a column. Observing color changes in reactions is about monitoring reaction progress or colorimetric tests, not separating components. Observing pH is about measuring acidity or basicity, typically with pH meters or indicators, not separating pigments.

Paper chromatography separates mixtures by moving components through a stationary phase (the paper) with a moving solvent. The different pigments in a material interact differently with the paper and with the solvent, so they travel at different speeds and form separate spots. This makes it possible to observe and compare the pigments present.

The description fits because it captures the main use of paper chromatography: to observe the different pigments that exist in a material, often by visualizing distinct colored spots on the paper.

The other ideas don’t fit as well: separating gases is done with gas chromatography, which uses a gas phase and a column. Observing color changes in reactions is about monitoring reaction progress or colorimetric tests, not separating components. Observing pH is about measuring acidity or basicity, typically with pH meters or indicators, not separating pigments.