Question

1. List two errors in the typical student set up for performing thin layer chromatography illustrated here. 2. Define the following terms: Analyte: Stationary Phase: Mobile phase: Solvent Front: Origin: Rf Value:

Answer 1

1. The set up has no lid. Generally the organic solvent system is volatile in nature. It evaporates in room temperature. If one runs TLC without covering the tlc chamber due to unsaturation of solvent vapor the results will be erroneous.

Another fault in this set up is layer of solvent in a tlc chamber should always be below the spots on tlc plate.

Which is not here.

2.

Analyte - The mixture of reagents kept in a particular solvent which is needed to be analyzed by tlc.

Stationary Phase - In thin layer chromatography there are two phase one phase holds the compound and remain stable it is generally silica and known as stationary phase and solid in nature.

Mobile phase - This is the phase which runs the analyte it is generally a solvent mixture generally analytes polarity is the determining factor whether it will remain in stationary phase or it will go with mobile phase.

Solvent Front - It is the maximum distance the mobile phase travels in a tlc plate.

Origin - It is starting line of analytes in a tlc plate. It is the position where the person spotted the material under analysis

Rf value - It is the ratio between the distance a particular travelled divised by the distance solvent travelled.

3. Compound y travelled 6.2 cm and solvent travelled 11.1 cm

Rf value = 6.2/11.1 = 0.558