A student investigated an orange dye (A) using paper chromatography. Figure 4 shows the results of Experiment 1 and Experiment 2 using orange dye A.

Explain why the yellow dye and red dye travel different distances in Experiment 1. Refer to forces of attraction between the dyes and the chromatography paper in your answer.

Paper chromatography separates substances based on their differential distribution between a stationary phase (the chromatography paper) and a mobile phase (the solvent, which is water in Experiment 1). - The **yellow dye** travels further up the paper. This indicates that it is more soluble in the mobile phase (water) and has weaker forces of attraction to the stationary phase (paper). It spends more time moving with the solvent. - The **red dye** travels a shorter distance. This indicates that it is less soluble in the mobile phase and has stronger forces of attraction to the stationary phase. It spends more time adsorbed onto the paper and less time moving with the solvent. The balance between solubility in the mobile phase and attraction to the stationary phase determines how far each component travels.