114. Solving a chemistry problem

A mixture of cadmium and iron (III) cations was separated by paper chromatography. A mixture of dioxane, antipyrine, and hydrochloric acid was used as the mobile phase. The mobility coefficients of these ions are 0.18 and 0.10, respectively. Under the same conditions, for the copper (II) cation used as a standard, Rf(st)=0.52. Calculate the relative mobility coefficients of zinc and iron(III) cations under the given conditions. Which of the two values Rf or Rs is a more objective characteristic of the mobility of a substance?