(i)     Calculate the ${R_{\text{f}}}$ values of A and B.

(ii)     Outline why compound B has travelled the greater distance.

(i)      ;

Award [1] for both correct.

(ii)     B is more soluble in solvent/mobile phase / B is less polar than A / B is less strongly adsorbed onto stationary phase;

Accept B is non-polar.

Do not allow “greater attraction/affinity to solvent” without reference to solubility.

(i)     Very well answered. Many candidates used an inappropriate number of significant figures for the calculated ${R_{\text{f}}}$ values, but this was not penalized in this instance. 

(ii)     Generally well answered. Some candidates successfully related the solubility of compound B to its polarity.