Rf Value Calculation in Paper Chromatography

Steps:

• Measure solvent front distance from origin (baseline) to front line.
• Measure distance from origin to center of each spot (A, B, C, D).
• Compute Rf for each: Rf = (spot distance / solvent distance).
• Compare to 0.37; spot B matches exactly.

Why B is correct:

• Rf = spot distance / solvent distance = 0.37 by definition, confirming B's position yields this value.

Why the others are wrong:

• A: Rf ≈ 0.25 (spot too close to baseline).
• C: Rf ≈ 0.50 (spot midway up paper).
• D: Rf ≈ 0.75 (spot near solvent front).

Final answer: B