Final answer:
In paper chromatography, polar molecules generally travel farther when a polar solvent is used, as they are better dissolved by polar solvents due to their affinity for such solvents. Conversely, non-polar molecules travel farther in non-polar solvents. The nature of the solvent in the chromatography process is critical for determining the mobility of substances on chromatography paper.
Step-by-step explanation:
In paper chromatography, whether polar or non-polar molecules travel farther depends largely on the nature of the solvent. Polar solvents are better at dissolving polar substances, which means polar molecules will travel farther in polar solvents due to stronger solute-solvent interactions. Conversely, non-polar solvents dissolve non-polar substances more effectively, enabling non-polar molecules to travel farther in such solvents. Additionally, polar molecules tend to align in an electric field, suggesting that they have different interactions with charged objects compared to non-polar molecules. However, all molecules are subject to London dispersion forces, with small polar molecules also experiencing dipole-dipole interactions.
Considering paper chromatography typically uses a polar solvent like water, polar molecules generally tend to travel farther due to their affinity for the polar solvent, which acts as the mobile phase. As the chromatography paper (stationary phase) is also polar, non-polar molecules do not adhere as strongly and thus might not travel as far as their polar counterparts. This is an important concept in chromatographic separation techniques where the affinity between molecules and solvents plays a key role in determining the movement of substances along the chromatography paper.