Determining the identity of unknown substances using the Rƒ factor found with chromatography paperPurposeTo separate molecules that are attracted to each other using the principles of forces intermolecular and a scientific relationship method for finding the identity of unknown substances.Theoretical basisChromatography corresponds to the solubility of substances in a mixture, as well as its ability to separate in different solvents. The level of separation is measured by a relative quantity, Rƒ, which compares the distance traveled by the molecule to the distance traveled by the solvent. This ratio can be calculated using the equation: Rf=D/L=(solute displacement distance)/(solvent displacement distance)Pre-Lab WorkHow can molecules attract each other when they are in a mixture? Predict how ethanol would interact with those molecules. Draw a picture that illustrates the interactions between the components of the mixture and the solvent, ethanol. Molecules attract each other to the opposite partial pole due to London dispersion and Coulomb force. The substances in a mixture are not chemically bonded. There are four types of intermolecular bonds with ethanol: London dispersion, dipole-dipole, covalent, and hydrogen. The ethanol will interact with the water and bind producing a tightly bound mixture, where the vegetable oil does not mix with the water molecules. These structures are represented in the following figure: What does the Rƒ value describe at a microscopic level? Why is this important? At a microscopic level the Rƒ value. This is important because it is used to determine the identity of substances and their solubility in various solvents. Furthermore, the Rƒ value affectsIf the molecule has a very high affinity for the stationary phase... middle of the paper...chromatography worked. Explain your picture using the following terms: stationary phase, mobile phase, solubility, and intermolecular forces. In the stationary phase (the paper), each substance is in its original mixture. The mobile phase (the solvent), is what transports the molecules onto the chromatography paper. This evaluation allows you to test the solubility of certain substances based on intermolecular forces, those whose bonds are weaker cross the mobile phase faster than those whose bonds are tighter and less soluble. Which molecule spent the longest time in the stationary phase and why? Bromithmol blue spends most of its time in the stationary phase because it is more polar, and molecules with greater polarity take longer to dissolve in the solvent and rise through the cellulose fibers of the chromatography paper.