Ion separation in paper chromatography

Steps:

• Identify X as Group I salt (e.g., NaCl), which typically shows single spot due to similar Rf for simple ions.
• Identify Y as transition metal salt (e.g., CuSO4), which may separate into colored spots from complex ions.
• Compare Rf values: Group I ions have higher solubility/mobility, traveling farther; transition ions slower due to adsorption.
• Match observed spots to choices: C shows Y with multiple/distinct colored spots, X with one.

Why C is correct:

• Transition elements form colored complexes with varying Rf, per chromatography principle of differential partitioning (like in Rf = distance traveled by solute / distance by solvent).

Why the others are wrong:

• A: Reverses X and Y behaviors, ignoring Group I simplicity.
• B: Assumes no separation for Y, contradicting transition ion diversity.
• D: Predicts identical Rf, violating solubility differences in aqueous media.

Final answer: C