Question

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 ____ x 10^-2.

Answer 1

Correct Answer: 25

To find the R_f value of the most polar compound, we use the formula:
R_f = (Distance traveled by compound) / (Distance traveled by solvent front)

• Distance traveled by compound A: 6 cm
• Distance traveled by compound B: 4 cm
• Distance traveled by compound C: 2 cm
• Distance traveled by solvent front: 8 cm

The R_f values are calculated as follows:

• Compound A: R_f = 6/8 = 0.75
• Compound B: R_f = 4/8 = 0.5
• Compound C: R_f = 2/8 = 0.25

The most polar compound will have the lowest R_f value, which is for compound C.

Therefore, the R_f value for the most polar compound C is 0.25.

Converting this value to the required format:
R_f = 0.25 x 10² = 25.

This falls within the given range of 25, confirming the solution is correct.