What is the mobile phase in column chromatography?

What is the mobile phase in column chromatography?

• A. Polar solvent only
• B. A mixture of polar and nonpolar solvents
• C. Nonpolar solvent only
• D. Pure water

Answer: (B)

The mobile phase is the solvent that moves through the column and carries the sample with it. Its polarity isn’t fixed; you tune it by mixing solvents to control how strongly analytes interact with the stationary phase. In practice, a single pure solvent often won’t give the right elution for all compounds, so a mixture of polar and nonpolar components is used and can be adjusted gradually (gradient) to achieve good separation. That’s why using a blend of polar and nonpolar solvents best captures how the mobile phase is typically prepared and how it operates in column chromatography.

The mobile phase is the solvent that moves through the column and carries the sample with it. Its polarity isn’t fixed; you tune it by mixing solvents to control how strongly analytes interact with the stationary phase. In practice, a single pure solvent often won’t give the right elution for all compounds, so a mixture of polar and nonpolar components is used and can be adjusted gradually (gradient) to achieve good separation. That’s why using a blend of polar and nonpolar solvents best captures how the mobile phase is typically prepared and how it operates in column chromatography.