Three layer liquid turns brown-yellow, blue and red.
name: Different substances dissolve in suitable solvents.
This experiment is based on different solubility of substances in different solvents. The ability of a solvent to dissolve different substances depends on such factors as hydrogen bounding, dipole moments and polarizability. The general concept, which describes the ability of a substance to form a solution in a defined solvent, can be formulated as “like dissolves like”.
Cooper sulfate is an ionic compound and a polar solvent is the best to dissolve it. Water is a polar solvent and is suitable for this purpose. The organic solvents are not polar and could not dissolve copper sulfate. The iodine molecule has nonionic structure. It is insoluble in water but when it is mixed with nonpolar chloroform iodine molecules experience the London dispersion forces. Iodine molecules are separated from each other in the original crystal structure by nonpolar solvent molecules. The color of the obtained solution is caused by the molecular form of iodine. It is violet similar to color of iodine vapor. In ethyl acetate iodine change its color due to the iodoform reaction:
2R-(C=O)-CH3 + 2OH- +3 I2 → 2R–(C=O)–O- + 2CHI3