What is the first step in the method of paper chromatography?

The first step in the method of paper chromatography involves drawing a pencil line near the bottom of a sheet of filter paper. This line serves as a baseline for applying the sample, such as ink or dye. The importance of this step lies in establishing a starting point for the chromatography process. The applied samples are dotted onto this line, ensuring that they remain above the surface of the solvent when the chromatography begins.

Using a pencil is critical because pencil marks are insoluble in the solvents typically used in chromatography, meaning they won't interfere with the separation of the dyes as they travel up the paper. Getting this step right is essential for ensuring clear and precise results in the analysis of the components in the mixture being examined.

Following this initial preparation, the next steps would involve adding the sample and then placing the paper in a beaker of solvent, and so forth, but those actions are dependent on the pencil line being established first.