Chromatography Efficiency Quiz

What is the equation that describes the efficiency of chromatographic columns?

• Newton's second law

• van Deemterequation

• Boyle's law

• Einstein's equation

What does the term A represent in the van Deemterequation?

• Column length

• Diffusion coefficient

• Multipath effects (eddy diffusion)

• Retention factor

What does the term B represent in the van Deemterequation?

• Retention factor

• Multipath effects (eddy diffusion)

• Diffusion coefficient

• Column length

What does the term C represent in the van Deemterequation for the stationary phase?

• Diffusion coefficient of the analyte in stationary phase

• Thickness of liquid coating on stationary phase

• Diameter of packing particles

• Retention factor

What does the term C represent in the van Deemterequation for the mobile phase?

• Diffusion coefficient of the analyte in mobile phase

• Diameter of packing particles

• Thickness of liquid coating on stationary phase

• Retention factor

What is the effect of eddy diffusion on band broadening in chromatography?

• It is independent of solvent velocity

• It is not affected by the quality of the packing

• It is directly proportional to the linear velocity of the mobile phase

• It decreases with high mobile phase velocities

What is the relationship between the B term and the linear velocity of the mobile phase?

• Directly proportional

• Inverse proportional

• No relationship

• Exponential relationship

What is the effect of longitudinal diffusion on band broadening in chromatography?

• It decreases with high mobile phase velocities

• It is not affected by the diffusion coefficient

• It is independent of the quality of the packing

• It is more significant in GC than in LC

What is the optimal flow rate at which the plate height is a minimum in chromatography?

• uopt

• u min

• u average

• u max

What is the process in which species migrate from a more concentrated part of a medium to a more dilute region?

• Filtration

• Diffusion

• Evaporation

• Osmosis