JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Practical and Analytical Chemistry

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 1 0^{- 2}

Answer: 25

Solution

With a non-polar developing solvent such as hexane, the more polar a compound is, the more strongly it is held by the polar stationary phase and the shorter the distance it travels. Of the three spots the one that moves least is the most polar; it travels

2 cm

while the solvent front advances

8 cm

R_{f} = \frac{2}{8} = 0.25

Expressed as asked, the

R_{f}

value of the most polar compound is

25 \times 1 0^{- 2}

JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Integer answer

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