Chemistry - Surface Chemistry Question with Solution | TestHub

Question Explanation: Calculating the ${\mathrm{R}}_{\mathrm{f}}=\frac{2}{5}=410^{-1}=4$ value from a paper chromatogram. Concept: Paper chromatography.

Solution: The retardation factor ( ${\mathrm{R}}_{\mathrm{f}}$ ) is a ratio representing the distance travelled by a spot (the solute) compared to the distance travelled by the solvent front.

Calculation:

${\mathrm{R}}_{\mathrm{f}}=\frac{Dis\tan cetravelledbycompound}{Dis\tan cetravelledbysolvent}$

On chromatogram distance travelled by compound is = 2 cm

Distance travelled by solvent = 5 cm

So

${\mathrm{R}}_{\mathrm{f}}=\frac{2}{5}=4\times 10^{-1}=4$

Final Answer: 4