What technique is used to separate components of a mixture by allowing soluble substances to spread across filter paper?

Chromatography is the technique utilized to separate components of a mixture by allowing soluble substances to spread across a substrate, such as filter paper. This method takes advantage of the differences in solubility and the interaction of compounds with the stationary phase (the filter paper in this case) and a mobile phase (the solvent).

When the mixture is applied to the paper and subjected to a solvent, various substances move at different rates based on their affinities for the paper and the solvent. Some components will travel further, while others will remain closer to the starting point. This results in the separation of the components, making it a powerful analytical tool for identifying and quantifying substances in a mixture.

The other techniques listed are used for different purposes: filtration involves separating solids from liquids, distillation separates components based on differences in boiling points, and sublimation is a process that transitions substances from solid to gas without passing through the liquid phase. While all these methods are valuable in chemistry, they do not involve the separation of components through spreading on filter paper like chromatography does.