Today we were investigating how to separate a mixture of soluble chemical substances.
As the solvent (water) rises through the paper it dissolves the sample mixture, which will then travel up the paper.
Small particles travel further than large particles, due to the differences in solubility and their attractions with the paper.
Many common dyes and inks are water soluble and spread apart into the component dyes using water as a solvent. If the dye or ink you are testing does not spread out using water, it may be a permanent ink.
We also learnt how this a technique used by forensic scientists to help solve crimes.
