Which statement describes the stationary phase in TLC as accurate?

Which statement describes the stationary phase in TLC as accurate?

• A. It is nonpolar
• B. It is a polymeric coating
• C. Silica gel (polar) is coated on a glass plate
• D. It is irrelevant to separation

Answer: (C)

In thin-layer chromatography the part that stays fixed on the plate—the stationary phase—controls how far each compound travels by interacting with it. The classic setup uses silica gel, a polar solid, coated as a thin layer on a glass plate (or other supports). Those silanol groups on the silica create strong polar interactions, so more polar compounds stick to the surface and move more slowly, while less polar ones glide along with the mobile phase. So describing the stationary phase as silica gel coated on a glass plate captures the common, effective arrangement used to separate by polarity. Saying it’s nonpolar wouldn’t fit normal-phase TLC, and calling it a polymeric coating isn’t accurate for silica gel on a plate. And claiming it’s irrelevant to separation ignores the central role the stationary phase plays in determining how far each component travels.

In thin-layer chromatography the part that stays fixed on the plate—the stationary phase—controls how far each compound travels by interacting with it. The classic setup uses silica gel, a polar solid, coated as a thin layer on a glass plate (or other supports). Those silanol groups on the silica create strong polar interactions, so more polar compounds stick to the surface and move more slowly, while less polar ones glide along with the mobile phase. So describing the stationary phase as silica gel coated on a glass plate captures the common, effective arrangement used to separate by polarity. Saying it’s nonpolar wouldn’t fit normal-phase TLC, and calling it a polymeric coating isn’t accurate for silica gel on a plate. And claiming it’s irrelevant to separation ignores the central role the stationary phase plays in determining how far each component travels.