In paper chromatography, what is referred to as the mobile phase?

In paper chromatography, the mobile phase is the solvent that moves through the stationary phase, which is the paper. The mobile phase carries the substances present in the mixture, allowing them to travel at different rates based on their solubility and affinity for the paper. As the solvent moves upward, it transports the compounds with it, leading to separation. The differences in how far each substance travels is what allows for the separation and analysis of the components within the mixture.

This process relies on the characteristics of the components, such as their polarity or size, and their interactions with both the solvent and the paper. Therefore, the correct identification of the mobile phase as the solvent is crucial in understanding how paper chromatography effectively separates the different substances present in the original sample.