Question

Arrange the following in order of increasing Rf on thin-layer chromatography: octanoic acid, butyraldehyde, 2-octanone, decane, and 1-pentanol.

Answer 1

Arrange the following in order of increasing Rf on thin-layer chromatography:

octanoic acid, butyraldehyde, 2-octanone, decane, and 1-pentanol.

In TLC more polar component has a stronger interaction with the polar Stationary phase and is therefore adsorbed on Stationary phase strongly.

As a result this strongly bonded move the less distance on TLC plate while , the less polar compound moves higher up the plate and gives higher R_f value.

The order in polar solvent or polar mobile phase:

Dacane < 2-octanon, <1-pentanol. , butyraldehyde < octanoic acid

For non-polar mobile :

Dacane > 2-octanon, >1-pentanol> butyraldehyde > octanoic acid,