Answer:
Retention factor or [tex]R_f[/tex] value is defined as the ratio of distance traveled by the unknown to the distance traveled by the solvent front.
[tex]R_f=\frac{\text{ distance by unknown}}{\text {distance by solvent}}[/tex]
Putting in the values we get:
[tex]R_f_{X}=\frac{0.50cm}{3.0cm}=0.16[/tex]
[tex]R_f_{Y}=\frac{1.0cm}{3.0cm}=0.33[/tex]
As the [tex]R_f[/tex] value of Y is more than X , it follows that Y compound will be retained less strongly than the compound X. Thus Y is more polar than X.