Planar Chromatography

What is the primary force driving the movement of the mobile phase in planar chromatography?

• Gravity

• Capillary forces

• Centrifugal force

• Electrical force

Which of the following is a key advantage of thin layer chromatography (TLC)?

• High cost

• Limited solvent choices

• Minimal sample preparation

• Extensive sample preparation

The retardation factor (Rf) is calculated using which of the following formulas?

• Distance traveled by solute ÷ Distance traveled by solvent front

• Distance traveled by solvent ÷ Distance traveled by solute

• Distance traveled by solute + Distance traveled by solvent front

• Distance traveled by solute × Distance traveled by solvent front

In planar chromatography, resolution is defined as the distance between two spot centers divided by what?

• Total plate height

• Mean spot widths

• Mobile phase velocity

• Solvent strength

Which of the following is used for separating optical isomers in planar chromatography?

• Reverse phase

• Chiral stationary phase

• Normal phase

• Adsorption phase

Why are high vapor pressure solvents, like ethyl ether, preferred in TLC but not HPLC?

• They degrade HPLC columns

• They are too volatile for TLC

• They enhance separation in HPLC

• They are more expensive

Which of the following techniques is used for detecting zones in planar chromatography?

• X-ray diffraction

• UV fluorescence

• Gas detection

• Thermal imaging

Which property of the mobile phase is adjusted using solvents like hexane in normal-phase planar chromatography?

• Solvent polarity

• Flow rate

• Resolution

• Capillary force

In planar chromatography, the capacity factor (k) is related to which of the following?

• Retention factor and spot width

• Time spent in stationary and mobile phases

• Plate height and flow rate

• Resolution and efficiency

Which development chamber type requires the use of filter paper for equilibration in HPTLC?

• Flat-bottom chamber

• Twin-trough chamber (TTC)

• Horizon chamber

• Open-air chamber