Three organic compounds A, B and C were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The R$$_f$$ value of the most polar compound is _____ $$\times 10^{-2}$$

1. Points of TLC

• Stationary Phase: Usually a polar substance like silica gel attached to the TLC plate.
• Mobile Phase: The solvent used to move the compounds. In this case, hexane is used, which is a highly non-polar solvent.
• Polarity vs. Distance: Since the stationary phase is polar and the mobile phase (hexane) is non-polar, a more polar compound will adhere more strongly to the plate and travel a shorter distance. A less polar (more non-polar) compound will dissolve better in hexane and travel further up the plate.

2. Identifying the Most Polar Compound

Looking at the distances traveled by each compound from the baseline:

• Distance traveled by Compound A = 6 cm
• Distance traveled by Compound B = 4 cm
• Distance traveled by Compound C = 2 cm

Since Compound C traveled the shortest distance (2 cm), it interacted the strongest with the polar stationary phase. Therefore, Compound C is the most polar compound.

3. Calculating the Rf Value

The Retardation Factor (Rf) is calculated using the formula:

From the given image:

• Distance traveled by Compound C = 2 cm
• Total distance traveled by the solvent front = 8 cm

Plugging these values into the formula:

4. Matching the Question Format

We can convert 0.25 into scientific notation matching this layout:

Correct Answer: 25